








1 


\ 


7 



i 


f 





* 

4 



\ 

. l • 

: ♦ I 


: 




* 




I » 


i 







<r 

f 




4 1 ^ 

t, 



N • , . • 1 

■. •ry^. 


« 


OCT 12 1960 

Defense memo 2 August I960 

UBBABY op CONGBESS 



DECLASSIFIED 
By authority Secretary of 

OCT 1 2 1960 

Defense memo 2 August 1960 

LIBBABY Qf! CONGBESS 


SUMMARY TECHNICAL REPORT 
OF THE 

NATIONAL DEFENSE RESEARCH COMMITTEE 





This document contains information affecting the national defense of the United 
States within the meaning of the Espionage Act, 50 U. S. C., 31 and 32, as 
amended. Its transmission or the revelation of its contents in any manner to an 
unauthorized person is prohibited by law. 


This volume is classified CONFIDENTIAL in accordance with security regula- 
tions of the War and Navy Departments because certain chapters contain material 
which was CONFIDENTIAL at the date of printing. Other chapters may have 
had a lower classification or none. The reader is advised to consult the War and 
Navy agencies listed on the reverse of this page for the current classification of any 
material. 


Manuscript and illustrations for this volume were prepared for 
publication by the Summary Reports Group of the Columbia 
University Division of War Research under contract OEMsr-1131 
with the Office of Scientific Research and Development. This 
volume was printed and bound by the Columbia University Press. 

Distribution of the Summary Technical Report of NDRC has 
been made by the War and Navy Departments. Inquiries con- 
cerning the availability and distribution of the Summary Tech- 
nical Report volumes and microfilmed and other reference 
material should be addressed to the War Department Library, 
Room lA-522, The Pentagon, Washington 25, D. C., or to the 
Office of Naval Research, Navy Department, Attention: Reports 
and Documents Section, Washington 25, D. C. 



Copy No. 

240 


SUMMARY TECHNICAL REPORT OE DIVISION 18, NDRC 

VOLUME I 


WAR METALLURGY 


OFFICE OF SCIENTIFIC RESEARCH AND DEVELOPMENT 
VANNEVAR BUSH, DIRECTOR 

NATIONAL DEFENSE RESEARCH COMMITTEE 
JAMES B. CONANT, CHAIRMAN 

DIVISION 18 
CLYDE WILLIAMS, CHIEF 




WASHINGTON, D. C., 1946 


^f',^5f^NATIONAL DEFENSE RESEARCH COMMITTEE 







James B. Conant, Chairman 
Richard C. Tolman, Vice Chairman 
' ✓ ^S^Roger Adams Army Representative^ 

Frank B. Jewett Navy Representative^ 

Karl T. Compton Commissioner of Patents-^ 

Irvin Stewart, Executive Secretary 


\4rmy representatives in order of service: 


Maj. Gen. G. V. Strong 
Maj. Gen. R. C. Moore 
Maj. Gen. C. C. Williams 
Brig. Gen. ^V. A. W^ood, Jr. 


Col. L. A. Denson 
Col. P. R. Faymonville 
Brig. Gen. E. A. Regnier 
Col. M. M. Irvine 


-Navy representatives in order of service: 

Rear Adm. H. G. Bowen 
Capt. Lybrand P. Smith 


Col. E. A. Routheau 


Rear Adm. J. A. Finer 
Rear Adm. A. H. Van Keuren 
Commodore H. A. Schade 
^Commissioners of Patents in order of sendee: 

Conway P. Coe Casper W. Ooms 


NOTES ON THE ORGANIZATION OF NDRC 


The duties of the National Defense Research Committee were 
(1) to recommend to the Director of OSRD suitable projects 
and research programs on the instrumentalities of warfare, to- 
gether with contract facilities for carrying out these projects and 
programs, and (2) to administer the technical and scientific 
work of the contracts. More specifically, NDRC functioned by 
initiating research projects on requests from the Army or the 
Navy, or on requests from an allied government transmitted 
through the Liaison Office of OSRD, or on its own considered 
initiative as a result of the experience of its members. Proposals 
prepared by the Division, Panel, or Committee for research con- 
tracts for performance of the work involved in such projects 
were first reviewed by NDRC, and if approved, recommended 
to the Director of OSRD. Upon approval of a proposal by the 
Director, a contract permitting maximum flexibility of scien- 
tific effort was arranged. The business aspects of the contract, 
including such matters as materials, clearances, vouchers, pat- 
ents, priorities, legal matters, and administration of patent mat- 
ters were handled by the Executive Secretary of OSRD. 

Originally NDRC administered its work through five divi- 
sions, each headed l)y one of the NDRC members. These were: 

Division A— Armor and Ordnance 

Division B— Bombs, Fuels, Gases, & Chemical Problems 
Division C— Communication and Transportation 
Division D— Detection, Controls, and Instruments 
Division E— Patents and Inventions 


In a reorganization in the fall of 1942, twenty-three adminis- 
trative divisions panels, or committees were created, each with 
a chief selected on the basis of his outstanding work in the par- 
ticular field. The NDRC members then became a reviewing and 
advisory group to the Director of OSRD. The final organization 
was as follo^vs: 

Division 1— Ballistic Research 

Division 2— Effects of Impact and Explosion 

Division 3— Rocket Ordnance 

Division 4— Ordnance Accessories 

Division 5— New Missiles 

Division 6— Sub-Surface Warfare 

Division 7— Fire Control 

Division 8— Explosives 

Division 9— Chemistry 

Division 10— Absorbents and Aerosols 

Division 11— Chemical Engineering 

Division 12— Transportation 

Division 13— Electrical Communication 

Division 14— Radar 

Division 15— Radio Coordination 

Division 16— Optics and Camouflage 

Division 17— Physics 

Division 18— War Metallurgy 

Division 19— Miscellaneous 

Applied Mathematics Panel 

Applied Psychology Panel 

Committee on Propagation 

Tropical Deterioration Administrative Committee 


IV 


XFIDENTIAL 


NDRC FOREWORD 


A S EVENTS of the years preceding 1940 revealed more 
^and more clearly the seriousness of the world 
situation, many scientists in this country came to 
realize the need of organizing scientific research for 
service in a national emergency. Recommendations 
which they made to the White House were given 
careful and sympathetic attention, and as a result 
the National Defense Research Committee [NDRC] 
was formed by Executive Order of the President in 
the summer of 1940. The members of NDRC, ap- 
pointed by the President, were instructed to sup- 
plement the work of the Army and the Navy in the 
development of the instrumentalities of war. A year 
later, upon the establishment of the Office of Scien- 
tific Research and Development [OSRD], NDRC 
became one of its units. 

The Summary Technical Report of NDRC is a 
conscientious effort on the part of NDRC to sum- 
marize and evaluate its work and to present it in a 
useful and permanent form. It comprises some 
seventy volumes broken into groups corresponding 
to the NDRC Divisions, Panels, and Committees. 

The Summary Technical Report of each Division, 
Panel, or Committee is an integral survey of the work 
of that group. The first volume of each group’s report 
contains a summary of the report, stating the prob- 
lems presented and the philosophy of attacking 
them, and summarizing the results of the research, 
development, and training activities undertaken. 
Some volumes may be “state of the art’’ treatises 
covering subjects to which various research groups 
have contributed information. Others may contain 
descriptions of devices developed in the laboratories. 
A master index of all these divisional, panel, and 
committee reports which together constitute the 
Summary Technical Report of NDRC is contained 
in a separate volume, which also includes the index 
of a microfilm record of pertinent technical labora- 
tory reports and reference material. 

Some of the NDRC-sponsored researches which 
had been declassified by the end of 1945 were of suf- 
ficient popular interest that it was found desirable 
to report them in the form of monographs, such as 
the series on radar by Division 14 and the monograph 
on sampling inspection by the Applied Mathematics 
Panel. Since the material treated in them is not 
duplicated in the Summary Technical Report of 


NDRC, the monographs are an important part of 
the story of these aspects of NDRC research. 

In contrast to the information on radar, which is 
of widespread interest and much of which is released 
to the public, the research on subsurface warfare is 
largely classified and is of general interest to a more 
restricted group. As a consequence, the report of 
Division 6 is found almost entirely in its Summary 
Technical Report, which runs to over twenty 
volumes. The extent of the work of a Division can- 
not therefore be judged solely by the number of 
volumes devoted to it in the Summary Technical 
Report of NDRC; account must be taken of the 
monographs and available reports published else- 
where. 

The field of wartime research of Division 18 was 
metallurgy. The objective of the Division, under 
the leadership of Clyde Williams, was to aid in im- 
proving metallurgical processes and metallic mate- 
rials of war and in promoting the conservation of 
scarce and strategic materials. 

The Division was unique among the NDRC 
groups in that it carried out its technical functions 
through the War Metallurgy Committee, a coordi- 
nating unit of thirty outstanding metallurgists and 
engineers created by the National Academy of 
Sciences and the National Research Council. 

The metallurgical research program was not con- 
cerned with the development of any specific military 
equipment or finished product, but rather with mate- 
rials and processes. Yet, though the program had no 
startling device to advertise it, its results were liter- 
ally built into planes and rockets, ships and guns and 
tanks. 

The Division’s Summary Technical Report has 
been prepared under the direction of, and has been 
authorized for publication by, the Division Chief. 
To him, to the divisional staff, to the members and 
staff of the War Metallurgy Committee, and to 
workers in the many contracting laboratories go our 
appreciation and thanks. 

Vannevar Bush, Director 
Office of Scientific Research and Development 

J. B. CoNANT^ Chairman 
National Defense Research Committee 


lONFIDKNTLAL 


V 





3 


V ’ 


* •• ^ 




■_L. ■ 


- 


• < J 


!, 


I • 


4 V. • 


III 




* P 


v<FV*- » 


'*■■ 1 ,' * 


.'."H • 'tV ... 


6 *^ 


i ^ 


..ji • 


* **.ii * '!9P 








f^i\ 


4 -: . ,'*,. ,t'> ^ V 






. -"r' L',i i_ ' ^'* - if. 



iVl 


hi.*-"* 


•rf -*^'v’'s-v»r * . s* ^ . 

'*3 '.tr* 

. “*.*, •.< , 1 . t ; ... jfcf ii, 


J M , 


*!W. 


T» 


I I 


•1 ' 

\ :• I*, * 


O' 


I 


b . • I 








■I <1 




■ ■ * •< *t' ».' . 'V • £,'■ 




•- .1* 


A - 


I' r I 


- I 




1.1 : i; 




I I • 


•i- 


•:Vr' 


!<. I ^1 * 


PJ^V'' •"'is fe*- Ar"%' 

' * *' ■' * * ''■ ' * ’ " ^ ' 

^ > j|g^ r ‘ 






'^1'- 




. (14 


r; 


, ' '■■■ ^ f ' ?■ !>*’ I •’ “’ ' ' ■ / ^'-' 1 ^ 


w‘!. I 


V* 


> >¥ 


|.» 




» 


4 > 


■/ i 


; ) 








• > / 


v- 

■ ‘ ^ f » 


fy ■ 


.Jf:^ ^ 


. t . 


ir’ I - -#:W 


r d^J 4 • ' 

■ \W; 


•' p* 




'♦ 




il-x 


fe, '* ■ ' * 

“ V>: 


< » . 



' ’ jA' • t /. VI f. 4 


> t 


' I'TTiJi 


#»• ;. 


. ^•^"•, n^-t* ", 




. • I 




v*> 





' 2 ' 


:}y.^ 

'* " ' ... 

I t / -. *' .^r U'*'-.'^ ■ ^ Vf * 

•;■». ■>■- •. , j')^- I 'V.V, li;,'-“ 


'■*1' 


. •£' is’ 0 /([ 4 .. ‘i. 

1 ■ : L» r ; . ' ti 


4f 





■ ■jW'W'- j • ' •*’■' ■, .,?*»k 


•'ifJ 


./ I 


a 'if 

I A f. • 


■f’x 


!/*>* ■ TS,V ^ ^ 


V t 


I 'M ^ ,’. ■ /tl; 






\* 

f 

f 

X . ■ 

• s' 1 

t 


■‘i 

f 

iv, 

1^ 




‘QP'-., ,'fe'‘-^;'":jj,v 4 ^’.. -i^i'^vC''''''’' '"'' 


E! 


■i 

I 


1 1 


• #'S^ 








FOREWORD 


T he following summary technical report of the 
work of the War Metallurgy Division (Division 
18) of the National Defense Research Committee 
[NDRC] gives a complete picture of the aims and 
accomplishments of the Division’s research program 
described in such detail as seems adequate. To this 
presentation the Division Chief has nothing to add 
by way of technical comment or emphasis. 

I do wish, however, to make acknowledgment to 
the editor, David C. Minton, Jr., for his painstaking 
work in assembling, or himself writing, the several 
sections of the report and in editing and coordinat- 
ing the entire report. He already has made acknowl- 
edgments in his preface to those who prepared the 
original manuscripts for the several sections and 
who otherwise assisted in the work. In all these 
acknowledgments I wish to join. 

After the specific acknowledgments in this report 
have been made, there still remains a very great 
indebtedness on the part of the War Metallurgy Divi- 
sion to many other agencies, organizations, and in- 
dividuals. 

The work of Division 18 was to undertake re- 
search to improve metallurgical processes, to improve 
metallic materials of construction, and to promote 
conservation and substitution of scarce or strategic 
metallic materials, all as applied to the production 
of instrumentalities of war. Recognition of the de- 
sirability of the coordination of defense and war 
research in metallurgy with industry and with re- 
search agencies and technical societies prompted the 
Office of Scientific Research and Development 
[OSRD] and NDRC in 1941 to enlist the assistance 
of the National Academy of Sciences and the Na- 
tional Research Council as channels through which 
NDRC metallurgical research might be accom- 
plished. 

The Division’s thanks are tendered to OSRD and 
NDRC for providing and supporting this channel 
of operation and to the National Academy of 
Sciences and the National Research Council for 
organizing and operating within their framework 
the War Metallurgy Committee to make effective 
the desired cooperative effort in metallurgical re- 
search. This cooperative effort was made possible by 
the members of the War Metallurgy Committee and 
several hundred industrial and university metal- 
lurgists, engineers, and research workers who served 
on the various project advisory committees, their 


time and technical advice being contributed by their 
employers without charge. 

In addition to contributing advice, industry gave 
without restrictions its accumulated knowledge, re- 
sults of research, and helpful comments and criticism. 
This invaluable information was used by the War 
Metallurgy Committee in appraising problems and 
in planning and directing the research projects of 
the Division’s program. The members of the War 
Metallurgy Committee and of the many project ad- 
visory committees, who together represented all 
phases of the metallurgical industry, were kept in- 
formed of the progress of the investigations so that 
the results could be utilized immediately in their 
research work and in war production. This free inter- 
change of information and ideas was particularly 
desirable in the work of the War Metallurgy Com- 
mittee because its greatest value lay in obtaining and 
disseminating industrial “know-how” so that in- 
strumentalities of war could be made from materials 
available, often using substitute materials which 
required special methods of processing. This is in 
contrast with much of the other work of NDRC 
which was concerned with the development of spe- 
cific military devices or finished products. Thus, the 
Division was able to provide information not only 
for the use of the Armed Services and their contrac- 
tors, but also for the use of other Divisions of NDRC. 

The accomplishments of the Division, which were 
made possible by the activities of the War Metal- 
lurgy Committee, provide an outstanding example 
of the results of cooperation between industry and 
governmental agencies in time of emergency. Thus, 
the Division’s activities throughout were truly co- 
operative and coordinating. The Division is fully as 
proud of its accomplishments in these aspects of its 
work as in any technical accomplishments, and by 
the same token it is sincerely grateful to all who 
helped in this cooperation. 

The Division is indebted and grateful also to the 
Armed Services, not simply for the formally desig- 
nated liaison, but for the sincere and active interest 
and participation in the Division’s program by all 
echelons of the Services’ research and development 
organizations. 

Clyde Williams 

Chief, Division 18 


CONFIDENTIAL 


!IVv 



. I .n . 

, .‘Sw’uii' i ' 

K.in •■*■ iiPF . ▼ 


far 




f pa 


t. 

• J (* 


■ r * 

}P , '■ 


- ^ * r 

■i- ■ ^ « 

V* 


\ 




. "'t- *»' v’’ 


:-‘- >: 


■ (• 
rft 


'V 

I 


t - - 


.» •“ 


I 4 


*■'- • 


J.' * 


r 


l#..;V 


i* 

f- r* 






v«' 


I'ifflV 


' « 






S^' 


•i' M 



^ r* 

V 


r , . 


» « 


£ • 


I 




■ t 



f., 


.sife/. 


Ip* 

r • 


I’t 




m 





'f\ ? 


%> ^ 

luk- ••■''i;V4=»^ 

v« * 

9 

V 

» » 

o 

f .■.,: 

1 



S^- 

; ’; 

1 




* * a ^ 

,. 'fc.* - 

L ^ - r " j . 

1' ,» ■ 


^ ■ 

bat^nf 


» 

r 


* # 


h*> 


Sf *'• 






1» V'^IM 


»i 


t* 

k ; * ‘ •V*, 

♦ 


:\i)* 


,*rl- 



,1 




'‘*•^1 '- flit ; 

* > . ' ?.*.• 


# »•' y\ ► 

" ’ ■ 


PREFACE 


T his report summarizes the metallurgy work on 
instrumentalities of warfare carried out under the 
direction of the War Metallurgy Division (Division 
18) of the National Defense Research Committee 
[NDRC]. 

The first purpose of this report is to serve as a guide 
to help the future student of the original reports to 
select those dealing with the subject in which he is 
interested. Often a number of projects relate to the 
same general topic. 

A second object is to give a broad view of the results 
obtained and of their engineering meaning, which 
may sometimes in itself be sufficient for the reader’s 
purpose, but more often may guide him to the par- 
ticular report that he will want to consult for details. 

In this connection, an attempt has been made to 
phrase the report so that the meaning of the results 
will be clear to a reader with general engineering 
background, even though he is not a metallurgical 
expert. However, some of the projects are so tech- 
nical and specialized that a reader must be something 
of an expert in the particular field to grasp even a 
not-too-technical report. Reports on such topics prob- 
ably will be referred to only by experts, so it has not 
been considered necessary to define technical terms 
or to discuss the elementary fundamentals involved. 

The projects discussed in this report were given a 
place on the war research program because experts 
believed that information on them could be used to 
further the war effort. They were carried only as far 
as it appeared that the information would be useful 
in World War II, although their further prosecution 
in more leisurely fashion might be of value in com- 
mercial problems or as a measure of preparedness 
against a future war. 

However, there are some projects in which matters 
were brought to such a stage that continuation and 
expansion of the research programs obviously should 
go on without interruption after demobilization of 
NDRC. In these cases, further work by or for the 
Armed Services usually has been arranged, and, since 
the situation is continually changing, it appears un- 
desirable to go into detail relative to such projects in 
this report. 

An appraisal of the direct and indirect influence of 
the work in some quantitative terms would be inter- 
esting, but the present writers, unable to make such 
an appraisal, have not attempted it. Such an ap- 
praisal could be made only by the Armed Services. It 


would be a very difficult task, since many tributaries 
fed the main stream of advancing knowledge of the 
production and the processing of metals and alloys. 
Service and civilian engineering and research, the 
civilian work directly sponsored by the Armed 
Services, work of the other NDRC divisions and of 
the War Production Board [WPB], as well as studies 
carried on under still other auspices all blended to- 
gether; and it would be virtually impossible to 
determine which drop of water in the main stream 
came from which tributary. That there already was 
considerable water in the stream is indicated by the 
fact that the bibiiographyi on armor, armor-piercing 
projectiles, and the welding of armor prepared by 
Watertown Arsenal contained 1,197 entries on 
armor, 457 on armor-piercing projectiles, and 121 on 
welding. This bibliography covered work only 
through 1942. 

In accordance with the instructions issued for the 
preparation of this report, no attempt has been made 
to allocate credit to the individuals who contributed 
to the work done. Rosters of the supervisory and ad- 
visory personnel appear in the back of the volume. 
Although the institutions where the research was 
carried out are mentioned in the text of this report, 
the bibliography must be consulted for the names of 
the authors of the reports who were, in most instances, 
the principal investigators. The names of those who 
supervised the work in behalf of the government and 
those who served on the many project advisory com- 
mittees are given in the distribution lists of the 
various reports cited in the bibliography of this 
report. 

This summary technical report is based in part 
on an editorial summary of most of the reports of 
Division 18 that was written by Dr. H. W. Gillett, 
a member of Division 18 and of the War Metallurgy 
Committee. Indeed, much of Dr. Gillett’s summary 
has been incorporated verbatim into this summary 
technical report by those who prepared the several 
chapters. Chapter 2, “Armor,” was prepared by 
Dr. C. H. Lorig of Battelle Memorial Institute and 
Supervisor of Armor Metallurgy Research, War Met- 
allurgy Committee. Most of Chapter 3, “Guns and 
Gun Steels,” was prepared by Dr. Cyril Wells, an in- 
vestigator on the NDRC gun steel projects at Carnegie 
Institute of Technology. The armor and ordnance 
section of Chapter 6, “Welding,” was prepared by 
Dr. A. Muller; the section on ship welding and 


CONFIDENTIAL 


ix 


X 


PREFACE 


welded steel ships of the same chapter was prepared 
by Dr. Finn Jonassen. Both of these men are Assistant 
Supervisors of Welding Research, War Metallurgy 
Committee. Chapter 5, “Metals for High Tempera- 
ture Research,” was prepared by Mr. Howard C. 
Cross of Battelle Memorial Institute and Supervisor 
of High Temperature Metals Research, War Metal- 
lurgy Committee. Chapter 1, “Aircraft Materials”; 
Chaper 4, “Ammunition”; Chapter 7, “Foundry 
Materials and Processes”; Chapter 8, “Enemy Mate- 
riel”; and Chapter 9, “Miscellaneous Materials for 
War,” were prepared by Mr. David C. Minton, Jr., 
Senior Technical Aide, Division 18, and Research 
Supervisor, War Metallury Committee. The Sum- 
mary was prepared by Mr. V. H. Schnee of Battelle 
Memorial Institute and Chairman, Products Re- 
search Division, War Metallurgy Committee, under 


whose charge the technical administration of the 
work of Division 18 was conducted. 

In addition to those named above, the editor 
acknowledges with thanks the assistance of Mr. Louis 
Jordan, Technical Aide to the Chief, Division 18, 
and Executive Secretary, War Metallurgy Com- 
mittee; and Mrs. S. L. Kruegel, Technical Aide of 
Division 18 as well as of the War Metallurgy Com- 
mittee. 

In the editing and compiling of this report, con- 
siderable license was taken with the material pre- 
pared by those named above in order to make the 
report as uniform as possible. 

David C. Minton, Jr. 

Editor 


CONFIDENTIAL 


-mu2 dliJ 1o md>o 3x13 , 301 x 1 lov eiiiT 

•jnw fi33d £fiii ,D^(1W lo Jioqsil toiiiri^^T vriini 
.!mi»¥3rq jfi 3 ng i^bno bdJniiq bnus .031 

lacq bdqqila 3 Vbi 1 rfjidv/ nons otb aiadj Ykisimfil 
3d Vim siadT ^lobssiiooiq Ims aiabssi ffoi»ivi(J 
aifr .^nijnhq }o ^raij ib nwoni Jon \o aioiid 
aid dgoo'oiJ wolfoi oj 3ldB a 3 t>d Jo« eed lodJuB 
.looiq ajjsq knd QJ^ydinw 

;o3 ziorno noqsi 

oBAoa rmu^iojJL'na avtA Twiot 

(AT/jiaa Bra) Koiaivin aMABooBB 
^ .a ,(:t J^OTOVUHaAW 

daarij nicnl boUqmoo 3d Iliw 3331 !* £jsn 5 79 )e£m A 
luoY ,3awlov 3ri3 lo aj£i3£qb3i oj Jnoa boii anoq 3 'i 
ladjo OJ luloisj 3'iom ;lood aidi sififxi Iliw qbri 

^nfi ^iiiiBqs iq ni 3 «!bv jByig k) 3d Ifiw bou mbsar 

.anoiaivai 


This volume, like the seventy others of the Sum- 
mary Technical Report of NDRC, has been writ- 
ten, edited, and printed under great pressure. 
Inevitably there are errors which have slipped past 
Division readers and proofreaders. There may be 
errors of fact not known at time of printing. The 
author has not been able to follow through his 
writing to the final page proof. 

Please report errors to: 

JOINT RESEARCH AND DEVELOPMENT BOARD 
PROGRAMS DIVISION (STR ERRATA) 

WASHINGTON 25, D. C. 

A master errata sheet will be compiled from these 
reports and sent to recipients of the volume. Your 
help will make this book more useful to other 
readers and will be of great value in preparing any 


revisions. 


CONTENTS 


CHAPTER PAGE 

Introduction 1 

Summary 5 

1 Aircraft Materials 11 

2 Armor 34 

3 Guns and Gun Steels 51 

4 Ammunition 74 

5 Metals for High-Temperature Service 81 

6 Welding 87 

7 Foundry Materials and Processes 107 

8 Examination of Enemy Materiel 114 

9 Miscellaneous Materials for War 117 

Bibliography 131 

OSRD Appointees 153 

Relationship Between War Metallurgy 

Committee and the Various Government Agencies . . . 154 

Members of the War Metallurgy Committee 155 

Staff of the War Metallurgy Committee 156 

Army and Navy Projects 158 

Contract Numbers 162 

Survey Projects 166 

Index 167 


CONFIDENTIAL 


xi 




INTRODUCTION 


ORGANIZATION OF DIVISION 18 

T he personnel of the War Metallurgy Division 
(Division 18) comprised a chief, three technical 
aides, and four members. These are listed on page 
153 of this report. 

Division 18 carried on its functions through the 
War Metallurgy Committee of the National Acad- 
emy of Sciences and National Research Council, 
which was an outgrowth of earlier committees of the 
National Academy of Sciences and National Re- 
search Council. 

The W^ar Metallurgy Committee assumed the con- 
tinuing functions of several smaller advisory com- 
mittees; namely, the Technologic Committee on 
Manganese, which was appointed by the National 
Academy of Sciences in July 1940 at the request of 
the Advisory Commission to the Council for Na- 
tional Defense (later succeeded by the Office of Pro- 
duction Management which in turn was succeeded 
by the War Production Board); the Advisory Com- 
mittee on Tin Reclamation, which was appointed 
in September 1940 at the request of the Advisory 
Commission; the Advisory Committee on Metals and 
Minerals, which was formed in January 1941 at the 
request of the Office of Production Management; 
and the Metallurgical Advisory Committee and the 
Welding Advisory Committee, which were formed 
as a result of a request of the Office of Scientific Re- 
search and Development in July 1941. 

It soon became apparent that the last two com- 
mittees could be combined to advantage, since many 
of the technical problems involved in the develop- 
ment of new weapons involved not only metallur- 
gical improvements but also definite advances in 
welding techniques and materials. The Metallur- 
gical Advisory Committee which began to function 
in October 1941 undertook to develop the necessary 
welding research programs as well as a metallurgical 
research program. In March 1942, the Metallurgical 
Advisory Committee was asked by the War Produc- 
tion Board to organize and supervise research in the 
field of production of metals and minerals. In May 
1942, it began the organization of a comprehensive 
research program financed largely by the War Pro- 
duction Board. 


In order to operate these various activities effi- 
ciently, in May 1942 the War Metallurgy Committee 
was organized. The relationship between the War 
Metallurgy Committee and the various government 
agencies which it served is shown diagrammatically 
on page 154. 

The committee proper was made up of 30 of the 
nation’s outstanding scientists, metallurgists, and 
engineers including 26 civilians, 3 Army officers, and 
1 Navy officer. The committee laid down broad prin- 
ciples and acted as an overall advisory committee. 
Although it met in a body only once each year, 
smaller groups of the members met from time to 
time to discuss specific problems in their fields and 
many decisions were arrived at through balloting by 
mail. A listing of the members of the War Metallurgy 
Committee is given on page 155. 

The administration of the committee was under 
a chairman who was responsible for overall opera- 
tions, a vice-chairman who was responsible for ad- 
visory reports and technical surveys, and an executive 
secretary who was responsible for administrative 
matters. 

The activities of the committee were carried on 
by four major divisions, each of which was in charge 
of a chairman whose duties were similar to those of 
a section chief in the usual NDRC division: 

1. The Advisory Division, which prepared reports 
for, and at the request of, the War Production Board 
primarily, but also other government agencies and 
the Army and Navy. 

2. The Processes Research Division, which was 
responsible for the organization and supervision of 
research projects, largely for the War Production 
Board, dealing with the development of new or im- 
proved processes for the production of metallic or 
mineral products and for the conservation and sub- 
stitution of materials. 

3. The Products Research Division, which was 
responsible for the organization and supervision of 
projects dealing with development or application 
of new or improved products and fabrication proc- 
esses for instrumentalities of warfare. Most of these 
projects were conducted for the National Defense 
Research Committee [NDRC] of the Office of Scien- 
tific Research and Development [OSRD]. 


1 


2 


INTRODUCTION 


4. The Research Information Division, which had 
charge of the collection and dissemination of classi- 
fied or unpublished information in the field of metals 
and minerals as a service to the research divisions 
and to the contractors under their supervision. 

In the work of the Advisory Division, emphasis 
was placed on bringing to bear on every question or 
problem submitted by government agencies the best 
talent and all of the scientific and practical informa- 
tion available to the committee through the large 
number of specialists serving on its subcommittees. 
The work of the Advisory Division was performed 
by the Advisory Committee on Metals and Minerals, 
one of the forerunners of the War Metallurgy Com- 
mittee. This Advisory Committee was comprised of 
70 specialists who were selected because of their abili- 
ties, not their positions. The basis for the selection of 
this committee, as with subsequent committees, was 
experience, judgment, and leadership in the particu- 
lar field of activity. The Advisory Committee on 
Metals and Minerals comprised five groups: 

1. Metals conservation and substitution group. 

2. Ferrous minerals and ferro-alloys group. 

3. Tin smelting and reclamation group. 

4. Nonmetallic minerals group. 

5. Alumina group. 

The Advisory Division and its predecessors have 
prepared a total of 200 reports touching on the fields 
of practically all the important metals and involving 
studies of new methods of production, recommenda- 
tions for the substitution of one metal for another 
and of other materials for metals, and suggestions 
as to how scarce metals could be conserved. Most of 
these reports were prepared at the request of the 
War Production Board, although some were pre- 
pared at the request of various branches of the 
Armed Services, NDRC, the Defense Plant Cor- 
poration, and the National Advisory Committee for 
Aeronautics [NACA]. Many included confidential 
company information which was made available to 
the committee by industry for the use of the various 
government agencies in making decisions concerning 
war production. 

In the work of the research divisions, emphasis 
was placed on close supervision of each project by a 
competent research director who was provided with 
the constant advice of committees of experts in the 
particular field concerned. In carrying out the re- 
search program, 32 research supervisors were em- 
ployed. Each of these supervisors had charge of one 


or more projects in his field and visited them from 
time to time to consult with and advise the inves- 
tigator on his research program. The research super- 
visor also coordinated the work of the related proj- 
ects in his field and consulted with representatives 
of the government agencies interested in the work. 
The duties of a research supervisor of the War 
Metallurgy Committee were similar to those of a 
technical aide in the usual NDRC divisional or- 
ganization. Each project or group of related projects 
had a project committee which assisted the super- 
visor in outlining his program and establishing tech- 
nical policy. These committees consisted of experts in 
the particular fields concerned as well as liaison rep- 
resentatives of the government agencies interested in 
the problem under study. In this manner, advice 
from those experienced in the field as well as from 
those who needed the information was available to 
the supervisor and through him to the project inves- 
tigator. Meetings of the project committees were held 
at frequent intervals to review the results of the work 
done when phases of the program were completed 
or when recommendations as to the continuation of 
the project or changes in the program were necessary. 

Each research supervisor and his project commit- 
tees were kept informed of the progress of the work 
on each project under his supervision through in- 
formal monthly reports and formal progress reports 
prepared by the investigator on each project. 

The Office of the Executive Secretary of the War 
Metallurgy Committee not only handled the collec- 
tion, duplication, and distribution of reports, but 
also served as a headquarters for the committee staff 
and records, maintained liaison with government 
agencies and the Armed Services, and performed 
numerous administrative functions. Among these 
were processing deferments for the contractors’ per- 
sonnel; obtaining the necessary priorities for the 
purchase of research supplies and equipment; ar- 
ranging for the security clearances of staff and con- 
tractors’ personnel; arranging for clearances for the 
staff members and contractors’ personnel to visit 
government laboratories, arsenals, proving grounds, 
etc., as well as other laboratories under government 
contracts; and keeping the staff and contractors ad- 
vised of new regulations affecting their activities. 

The Research Information Division collected in- 
formation from domestic and allied government 
sources, classified it, and distributed it to the various 
supervisors and investigators concerned so that they 


INTRODUCTION 


3 


could benefit by the efforts of other investigators 
working in their fields. This information included 
not only that of our government and allied govern- 
ment laboratories but also available information 
concerning the activities of the enemy in the field of 
metallurgy. The Research fnformation Division also 
maintained a staff of librarians who abstracted and 
indexed the research reports issued so that the infor- 
mation was correlated and made more readily usable 
by the government agencies, Armed Services, and 
their contractors engaged in war production.^’S 

A roster of the staff of the W^ar Metallurgy Com- 
mittee is given on pages 156-157. 

SOURCES OF RESEARCH PROBLEMS 

The research problems upon which the War Met- 
allurgy Committee program was based emanated 
from several sources. These are shown diagram- 
matically on page 154. Many projects were under- 
taken as the result of recommendations made by 
civilian ad hoc committees appointed by NDRC or 
the War Metallurgy Committee. Some projects were 
undertaken because the members or staff of the War 
Metallurgy Committee were familiar with problems 
of industry; others were studied at the request of the 
War Production Board. To avoid overlooking such 
problems vital to the war effort, the War Metallurgy 
Committee employed recognized experts to make 
surveys of the available information in their fields 
so that the gaps or research needs could be ascer- 
tained and research speedily initiated. 

Naturally, these gaps were in widely varied fields, 
the only necessary feature of similarity being that 
the problems all concerned metallurgy or metal- 
lurgical engineering in the war effort, fn rare cases, 
projects were undertaken that, on the basis of avail- 
able information, had but a slight chance of success. 
This was because the possibilities had not been ex- 
hausted and even a slight chance of success was worth 
taking. These were, in the main, unsuccessful and 
were terminated as soon as convincing evidence had 
been accumulated that, with present-day knowledge 
and facilities, hope of securing information in time 
for application in World War II was still vanishingly 
small. Many of the projects were on topics already 
under investigation by the Armed Services or already 
in the minds of their representatives as deserving of 
study when opportunity and funds permitted. When 
the Armed Services were unable to continue their 


work, a program was planned either to carry it on 
from whatever point the Services had reached or to 
dovetail it into their continuing work. These studies 
were requested of NDRC through the War Depart- 
ment Liaison Officer for NDRC, Headquarters, Army 
Service Forces, or the Coordinator of Research and 
Development (later the Office of Research and In- 
vention) of the Executive Office of the Secretary of 
the Navy. A listing of the Army and Navy projects 
assigned to Division 18 with the Division 18 projects 
pertaining to each is given in Appendix E. 

Almost all the projects established on problems 
relating to instrumentalities of war and originating 
outside of the Armed Services were subsequently 
adopted by the interested branches of the Services 
and appropriate liaison established so that they 
could be conducted with maximum benefit to the 
Services. 

ESTABLISHMENT OF RESEARCH 
PROJECTS 

After appraisal of a problem, a research program 
was formulated, and a contractor selected whose 
facilities, personnel, and experience might best be 
utilized to attack the problem and to conduct the 
program speedily and efficiently. Proposals for the 
financing of these projects were reviewed and ap- 
proved by the members of Division 18 prior to 
presentation to NDRC. As the War Metallurgy Com- 
mittee also supervised research on production, con- 
servation and substitution, and process metallurgy 
problems for the War Production Board, proposals 
for financing research on such problems were sub- 
mitted to the Office of Production Research and De- 
velopment [OPRD] of the WPB. (See page 154.) 

The types of projects established included research 
projects, correlation projects, and survey projects. 
The research projects involved laboratory investiga- 
tions and were financed by OSRD or OPRD under 
contracts between those agencies and the research 
laboratories. Correlation projects were investigations 
which were financed by industrial concerns but car- 
ried out under the general supervision of the War 
Metallurgy Committee, the results of the investiga- 
tions being submitted by the War Metallurgy Com- 
mittee to NDRC and distributed to the Armed 
Services and their contractors in the form of NDRC 
reports. Survey projects were field investigations car- 
ried out by engineers or committees designated by 


AL 


4 


INTRODUCTION 


the War Metallurgy Committee to collect and cor- 
relate the available information on a given subject 
so that the research needs could be determined. In 
many cases the information made available by indus- 
try was sufficient for government purposes and obvi- 
ated the necessity for establishing research projects. 

All contractual and fiscal relationships with the 
OSRD contractors under the jurisdiction of Division 
18 were the responsibility of and were conducted by 
the Division staff even though technical supervision 
and administrative duties were carried out by the 
^Var Metallurgy Committee. 

THE RESEARCH PROGRAM 
OF DIVISION 18 

The research program of Division 18 included the 
study of metallurgical problems involved in the pro- 
duction of materials and instrumentalities of war. 
The specific objectives of the work were to improve 
the qualities and properties of metals and alloys 
used in military vehicles, equipment, weapons, and 
ammunition; to improve the methods of producing 
and fabricating such metals and products; and to 
increase the production of such military products 
by the development of substitute materials having 
acceptable properties. Unlike most of the other 
NDRC divisions. Division 18 was never concerned 
with the development of a specific military device 
or of a finished product. The Division 18 work itself 
comprised fundamental research complemented by 
applied research designed to reduce the technical 
findings to the practical production of military goods 
by industry. 

The technical program of Division 18 as carried 
out under the supervision of the War Metallurgy 
Committee embraced 91 contract research projects, 
11 correlation projects financed by industry, and 21 
survey projects, or a total of 123 investigations on a 
wide variety of subjects. A listing of the Division 18 


contract and correlation projects is given on pages 
162-165. This listing also gives the contractual 
information for each contract, the name, address, 
and technical representative of each contractor, and 
the title of each project. A listing of the War Metal- 
lurgy Committee survey projects carried out for 
NDRC is given on page 166. 

For convenience, the Division 18 program has been 
subdivided by materials or processes in this sum- 
mary technical report in the same manner as in the 
semiannual Division 18 memoranda reports to the 
Office of the Chairman, NDRC. These broad sub- 
divisions, which are also chapters of this report, are 
as follows: 


Chapter 1. 
Chapter 2- 
Chapter 3. 
Chapter 4. 
Chapter 5. 
Chapter 6. 
Chapter 7. 
Chapter 8. 
Chapter 9. 


Aircraft Materials. 

Armor. 

Guns and Gun Steels. 

Ammunition. 

Metals for High-Temperature Service. 
Welding. 

Foundry Materials and Processes. 
Enemy Materiel. 

Miscellaneous Materials for War. 


The attention of the reader is called to a compre- 
hensive index2 of all the 661 Division 18 reports. 
As stated before, the War Metallurgy Committee 
also supervised research on production, conservation 
and substitution, and process metallurgy problems 
for the Office of Production Research and Develop- 
ment. These projects are not discussed in this report, 
but, in many instances, particularly in investigations 
of aircraft materials and welding, the OPRD work 
complements that of NDRC. An index*^ of the 163 
research reports and 200 advisory reports submitted 
by the War Metallurgy Committee to OPRD is given 
in the bibliography and will assist in giving the 
reader a better understanding of the overall picture 
of the metallurgical research carried out by NDRC 
and OPRD during World War II. 


CONFIDENTIAL 


SUMMARY 


E ach of the nine parts of the Division 18 research 
program consisted of a group of related projects 
concerned with metallurgical problems pertinent to 
the production of materials for instrumentalities of 
war. The program comprised fundamental research 
complemented by applied research to reduce the 
technical findings to the practical production of war 
materiel by industry. The specific objectives of the 
work were to improve the qualities and properties of 
metals used in military products, to improve the 
methods of producing and fabricating such metals 
and products, and to increase the production of such 
military products by the development of substitute 
materials having acceptable properties. A brief 
resume of the accomplishments of each of the nine 
parts of the Division 18 research program is given 
in the following summary, and more detailed treat- 
ment is given in the body of this report. 

AIRCRAFT MATERIALS 

This part of the research program was concerned 
primarily with the study of the light alloys, alumi- 
num and magnesium. The mass production of air- 
craft undertaken for the first time early in the war 
effort introduced a host of new problems. The transi- 
tion from hand forming and cut-and-try methods of 
fabrication to production practice called for the im- 
mediate collection and dissemination of a mass of 
fundamental data on the forming properties of the 
aluminum alloys. An extensive survey of industrial 
fabrication operations was undertaken, and a cor- 
related digest of the information was distributed 
widely through the aircraft industry by the Produc- 
tion Aids Unit, Bureau of Aeronautics, Navy De- 
partment. Based on this survey, three research proj- 
ects were established to secure needed additional 
information on the forming characteristics of alumi- 
num alloys. These projects were extended later to 
study the properties and forming characteristics of 
the stronger aluminum alloys which became avail- 
able during the war. 

Surveys to collect and disseminate information on 
the effects of impurities in aluminum alloys, on the 
fatigue and impact characteristics of the heat-treated 
alloys, and on the high-temperature properties of 


both magnesium and aluminum alloys were conduc- 
ted. A preliminary study of the possibilities of cast- 
ing or forging high beryllium-aluminum alloys for 
possible use in lightweight engine parts indicated 
great commercial difficulties and consequently was 
not carried to completion. 

Early in the war, there was considerable doubt 
that sufficient supplies of aluminum could be devel- 
oped in time to satisfy the leaping requirements of 
the aircraft production program. New and greatly 
increased production facilities for magnesium were 
authorized and ample supplies of this virtually new 
metal seemed assured. It appeared necessary to secure 
as rapidly as possible the engineering data which 
would permit the aircraft designers to evaluate or to 
use magnesium alloys in the construction of air- 
frames. Five research projects were established. Two 
of these were planned to study the mechanical prop- 
erties and the fatigue characteristics of the then 
available magnesium alloys. Two were concerned 
with studies of forming characteristics and another 
with the stress-corrosion of magnesium alloy sheet. 
Alloys with a high level of property values were not 
developed, but new techniques in casting and heat 
treatment resulted in increasing materially the re- 
sistance to stress-corrosion of certain of the commer- 
cial alloys. Work on the development of new mag- 
nesium alloys is being continued both by the Bureau 
of Aeronautics, Navy Department, and the Army 
Air Forces. 

Research on the development of carbon steel air- 
craft control cables, with adequate corrosion re- 
sistance, to replace stainless steel cables resulted in 
cable with improved performance characteristics and 
provided data for use in the revision of specifications 
covering aircraft control cables. A project on 
mechanical surface treatment made possible a sub- 
stantial improvement in performance of a number 
of engine and ordnance parts. In many instances, 
this treatment, shot peening, obviated the necessity 
for redesigning parts which had been put into pro- 
duction but were suffering premature failures in 
service. 

In order to assist in the standardization of test 
methods used in the procurement of aircraft mate- 
rials, a comprehensive survey was made of the test 


CONFIDENTIAL 


5 


6 


SUMMARY 


methods of the Materials Laboratory, Air Technical 
Service Command [ATSC], Wright Field. Another 
survey was carried out on the fatigue of aircraft 
structures and materials so that the research needs 
in the field could be ascertained. 

ARMOR 

Ten projects on the metallurgy of armor and armor 
steels were conducted. The principal project was 
a broad study of the fundamental metallurgical prob- 
lems encountered in the production and heat treat- 
ment of armor plate. Starting with problems of con- 
servation and substitution brought about by the 
critical shortages in alloying elements at the begin- 
ning of World War II, the work included studies of 
the effect of gas in armor steel, the correlation of 
metallographic structure and hardness of armor 
plate, the improvement of the ballistic properties of 
low-alloy armor plate, the effects of various elements 
on the quench-cracking susceptibility of cast armor, 
and the development of methods for the production 
of face-hardened armor plate. 

Supplementary projects were conducted to make 
more detailed investigations of the more important 
problems, notably the use of boron as a hardening 
element, the use of flame hardening, and the develop- 
ment of nonalloy armor plate. 

Other investigations were concerned with the de- 
velopment of a nonballistic test and a direct explo- 
sion test for armor quality. The nonballistic test was 
capable of predicting failure by spalling but was not 
reliable for predicting cracking. The direct explo- 
sion test showed considerable promise for use as a 
screening test prior to ballistic testing and as a 
method of eliminating much of the human equation 
in evaluating ballistic results. 

These projects were conducted with the close 
cooperation of Watertown Arsenal and the subcom- 
mittees on Cast and Rolled Armor, Ferrous Metal- 
lurgical Advisory Board, Army Ordinance Depart- 
ment. They resulted in improvements in practice for 
cast armor, improvements in face-hardened armor, 
and a better understanding of the role of composi- 
tion, gas content, and microstructure on the ballistic 
properties of armor plate. 

Another project of interest to the Bureau of Ord- 
nance, Navy Department, and the Army Air Force 
was an investigation of nonmagnetic or magnetically 
stable armor plate for aircraft. This included deter- 


mination of the ballistic properties of a number of 
nonmagnetic steel compositions made with various 
heat treatments. 

GUNS AND GUN STEELS 

Eight coordinated projects relating to gun tubes 
and gun steels were conducted in close cooperation 
with Watertown Arsenal, Watervliet Arsenal, and 
the Research Group of the Subcommittee on Gun 
Forgings, Ferrous Metallurgical Advisory Board, 
Army Ordnance Department. 

In this program, two projects were concerned with 
the quality of steel used in the manufacture of 
wrought gun tubes. Both laboratory and statistical 
studies were made, and as a result of these studies 
data were supplied for the revision of the specifica- 
tions for wrought gun tubes, making it possible to 
secure adequate quality of gun steel as well as the 
finished gun. Testing procedures were also simplified, 
thus making substantial savings in time and money 
with an overall increase in the number of satisfactory 
guns produced. Under a project on the improvement 
of gun steel ingot practice, a study was made of the 
relation between ingot practice and bore defects 
and of the effects of bore defects on the performance 
of 40-mm and 75-mm seamless gun tubes. A classifica- 
tion of bore defects based on these studies was pre- 
pared to assist in the inspection of gun tubes. Under 
a project on the prevention of cracking in gun tubes, 
a test for cracking susceptibility was developed, the 
causes of quench cracking were determined, and 
remedies were outlined for reducing quench-crack 
losses. Certain of these projects are being continued 
under contract with the Ordnance Department. 

A project on the control of basic open-hearth melt- 
ing practice for the manufacture of wrought gun 
tubes correlated the numerous manufacturing vari- 
ables with the quality and physical properties of 
gun tubes. Two other projects on the processing of 
wrought gun tubes dealt with the heat treatment 
of gun steels. One of these projects developed a 
test method for determining the correct tempering 
temperatures for fully hardened and tempered gun 
tubes. This method was adopted by manufacturers of 
gun tubes and resulted in the development of im- 
proved heat treating practices, materially decreasing 
rejections with a corresponding increase in finished 
gun tubes. 

At the close of World War II, a project was under 


CONFIDENTIAL 


SUMMARY 


7 


way to develop new gun steels with greatly improved 
properties for use in connection with new designs de- 
veloped by the Army Ordnance Department. 

AMMUNITION 

At the request of the Office of the Chief of Ord- 
nance, investigations were carried out on materials 
for three components of ammunition: armor-piercing 
shot, cartridge cases, and driving bands. 

The project on armor-piercing shot was concerned 
with studies of nonalloy steels treated with special 
addition agents and resulted in the development of 
armor-piercing shot with superior ballistic proper- 
ties. 

Three investigations relating to the stress-corro- 
sion cracking of cartridge brass were conducted with 
the close cooperation of Frankford Arsenal where 
work of a similar nature was being carried on. One 
project was concerned with the prevention of stress- 
corrosion by surface protection or treatment and re- 
sulted in the development of new protective coat- 
ings, one of which demonstrated the efficacy of thin 
electroplated zinc coatings and the electrochemical 
protection afForded to scratched areas. Under a proj- 
ect relating to the detection and elimination of 
internal stresses contributing to stress-corrosion, 
methods of measuring the stresses introduced in the 
cartridge case manufacturing processes by X rays 
were developed and applied to lots of sample cases 
from Frankford Arsenal to permit better production 
control. A study of the effect of volume changes 
associated with phase changes in cartridge brass re- 
vealed that the effect was negligible and that proper 
annealing eliminated the laminated structure caused 
by the presence of the zinc-rich phase. 

METALS FOR HIGH -TEMPERATURE 
SERVICE 

Work in this field was instituted at the request of 
the Navy Department to develop new alloys and to 
establish design data for the commercial alloys avail- 
able for high-temperature service in the gas turbine 
used for ship propulsion. In order to expedite the 
investigation, the facilities of 12 laboratories were 
utilized. Early in the investigation, it was recognized 
that the results were equally applicable to the high- 
temperature service encountered in the operation of 
turbosuperchargers and jet propulsion engines for 


aircraft. The work therefore, was closely correlated 
with the related research programs of the National 
Advisory Committee for Aeronautics, the U. S. Naval 
Engineering Experiment Station, the alloy pro- 
ducers, and the manufacturers of the equipment 
being supplied to the Armed Services. Thus, all types 
of test data were obtained over a temperature range 
from 1200 to 2000 F. 

Early in 1942, the Armed Services requested an 
alloy that would give satisfactory service at a 
temperature of 1500 F and at a stress of 7,000 psi. Six 
heat-resisting alloys of promise for gas turbine and 
turbosupercharger service were then available, but 
none possessed the desired properties at high 
temperatures. At the termination of the work, nearly 
one hundred alloys had been tested, and ten or more 
had been shown to possess properties at 1500 F equal 
to or considerably better than the original goal of 
the project. Several of the forged and cast alloys in- 
vestigated were shown to have as good properties at 
1600 F as those originally desired at 1500 F. 

Concurrent with the determination of design data 
at high temperatures for the available alloys and 
those of similar base compositions developed during 
the project, two of the laboratories were engaged in 
studies of the properties of new alloy systems. Limited 
tests on these new experimental alloys at 1600 F 
indicate these alloys to be superior in properties to 
presently available commercial alloys and of great 
future promise, but additional research work is need- 
ed to determine satisfactorily their properties and 
to develop suitable methods for commercial pro- 
duction. 

In addition to the foregoing investigations, a proj- 
ect on metal and ceramic materials for jet propul- 
sion devices was carried out in cooperation with the 
Armed Services, their contractors, and other NDRC 
divisions. Under this project, assistance was given 
on the development of materials of construction for 
both solid-fuel and liquid-fuel rocket motors. 

The research work on developing engineering 
data on heat-resisting alloys and the welding of these 
alloys is being continued under the sponsorship of 
the Office of Research and Invention, Navy Depart- 
ment. A comprehensive fundamental investigation 
of heat-resisting alloys and ceramic materials has also 
been sponsored by this agency. This work is closely 
correlated with the engineering studies now in prog- 
ress. 


CONFIDENTIAL 


8 


SUMMARY 


WELDING 

The welding research program comprised 29 lab- 
oratory projects, 14 of which were concerned with 
the welding of ordnance and aircraft materials, and 
15 with ship welding and welded steel ships. 

A large part of the programs of two of the prin- 
cipal projects on the welding or ordnance material 
dealt with the development of methods for welding 
low-alloy homogeneous armor and the development 
of a welding electrode which was substituted satis- 
factorily for the high nickel-chromium alloy com- 
monly used for welding of armor. This development 
provided not only a means for saving large amounts 
of nickel and chromium but also an electrode which 
produced welds with ballistic properties comparing 
favorably with those made with the high nickel- 
chromium types. Details of the properties and per- 
formance characteristics of this electrode were 
worked out so that Army Ordnance Department 
specifications could be written. In the later stages of 
World War II, work was done also leading to the ap- 
plication of this type of electrode to the repair weld- 
ing of cast armor. Also studied at the request of the 
Army Ordnance Department was the low- tempera- 
ture ballistic performance of welded armor plate in 
connection with the Canadian Cold Test Program. 

Fundamental studies of electrode coatings and the 
causes of weld metal porosity and underbead crack- 
ing were begun, but not completed. Under this proj- 
ect, however, an electrode was developed for the 
welding of high-strength structural steel such as 
is used in the fabrication of mobile gun mounts and 
other ordnance material. 

A direct explosion test was developed which holds 
promise for the easy and economic evaluation of 
welded armor and of prime plate. Other projects 
carried out dealt with the development of a ceramic 
backup strip, the effect of oxygen cutting on the 
weldability of armor plate, residual stresses in weld- 
ments and their relief, and the welding of face- 
hardened armor. 

Five projects concerned with investigating the 
weldability of alloy steels provided procedures and 
data of considerable value to industry in the im- 
provement of welding techniques. 

Spot welding and flash welding processes were in- 
vestigated to provide information on which wider 
application of these fabricating methods could be 
based. Nondestructive testing methods for welds 


made by these methods were investigated also under 
two projects. An interpretation of radiographs of 
spot welds which was developed under one of these 
investigations was adopted by the Bureau of Aero- 
nautics, Navy Department, in a specification. 

The research program to investigate the causes of 
failures of welded ship structures and to develop 
remedial measures was sponsored by the Coast 
Guard, the Maritime Commission, and the Navy 
Department. It was still in progress at the close of 
the war and is being continued under direct Bureau 
of Ships contracts. Studies completed, however, com- 
prised investigations of welding stresses in labora- 
tory scale specimens as well as the measurement of 
those in actual ship structures during fabrication and 
during voyages. Two investigations were completed 
also on the effect of combined loads on the behavior 
of ship steel. Continuing projects include studies 
of the weldability and metallurgical quality of steels 
for hull construction, the effect of notches and struc- 
tural discontinuities on the behavior of ship steel, a 
correlation of laboratory tests with full-scale ship 
plate fracture tests, and the fatigue of ship welds. 

FOUNDRY MATERIALS AND PROCESSES 

In order to assist in alleviating overloaded facili- 
ties for the manufacture of cast steel products and to 
make available a portion of the large productive 
capacity of the malleable iron industry, an investi- 
gation of the properties, particularly the low-tem- 
perature properties, of malleable iron for use in 
ordnance materiel was carried out at the request of 
the Office of the Chief of Ordnance. The results of 
this investigation provided data upon which the 
substitution of malleable iron for cast steel could 
be based. 

As in the case of malleable iron, it was believed 
that steel castings might to some extent replace forg- 
ings and thus relieve the pressure on forging facili- 
ties. Therefore, a research program on the centrif- 
ugal casting method was carried out. This program 
comprised a survey of the possibilities of the method 
and the research needs, preparation of a bibliography 
on centrifugal casting, study of the heat flow in 
metal molds, study of mathematics underlying the 
process, and experimental work to develop and ex- 
tend the process to the production of ordnance 
materiel. The methods proved successful for the 
experimental production of trench mortar barrels. 


SUMMARY 


9 


recoil cylinders, and other applications, and were 
applied in production. 

Precision casting methods were investigated also 
to ease the demand on forging and machining facili- 
ties. As a result of this work, the process was adopted 
by Watervliet Arsenal, the Naval Research Labora- 
tory, the Winchester Arms Company, and others, 
for the production of war materiel such as intricate 
parts for artillery and small arms mechanisms, and 
for other applications which required an extensive 
amount of hand work in their production. 

At the request of Watertown Arsenal, two refrac- 
tory problems were solved. They involved the de- 
velopment of a substitute for sillimanite in pouring 
rings and the development of an acceptance test for 
pouring box refractories. 

EXAMINATION OF ENEMY MATERIEL 

Captured enemy materiel was examined in order 
to determine significant changes in the composition 
of materials which might indicate impending short- 
ages in enemy supplies and in order to advise the 
Armed Services, the Foreign Economic Administra- 
tion, the investigators on the various Division 18 
research projects, and industry of enemy develop- 
ments that appeared to offer improvements or alter- 
natives in our production or military products. 

This project supplemented the work of the Armed 
Services and was conducted in close cooperation with 
the Army Ordnance Department Collection Center 
at Aberdeen Proving Ground, the Naval Technical 
Air Intelligence Center at Anacostia, and the Air 
Technical Service Command at Wright Field. In 
the 215 topical reports issued, 794 individual samples 
or shipments of diverse nature were covered, ranging 
from aircraft engines to machine guns. 

This project brought to the Armed Services the 
nation’s specialists on materials and their produc- 
tion and made available many of the nation’s indus- 
trial laboratories for special advice and service. 

MISCELLANEOUS MATERIALS 
FOR WAR 

Under this classification are grouped a number 
of investigations relating to studies of materials used 


for miscellaneous instrumentalities of warfare not 
included in the above-mentioned groups. 

At the request of the Office of the Quartermaster 
General, several investigations were undertaken. 
These comprised the development of noncritical 
fused inorganic coatings for steel canteens and cook- 
ing utensils, the development of plated steel flatware 
for military use, a study of the proper materials for 
use in a variety of products required by the Quarter- 
master Corps, investigation of methods of camouflag- 
ing mess gear, and the evaluation of the corrosion- 
resisting properties of an alloy that had been sug- 
gested for quartermaster’s items. 

The properties of a number of miscellaneous 
materials were also investigated. These projects in- 
cluded a compilation of the low-temperature proper- 
ties of metals, the behavior of metals under rapid 
rates of strain, and the effects of impurities on the 
ferromagnetism of nonferrous alloys used in instru- 
ments. 

Although most of the problems involving the con- 
servation, substitution, or processing of various ma- 
terials were sponsored by WPB, several NDRC re- 
search and survey projects in this field were con- 
ducted at the request of the Armed Services. The 
survey projects comprised a comprehensive study of 
the industrial applications of chromium plating to 
provide a basis for research on the use of chromium 
plating in war materiel, an appraisal of a proposed 
investigation on rivets and rivet steels, a study of the 
use of rare metals in electrical contacts and the pos- 
sibility of making substitutions of less critical metals, 
and a study of methods of reclaiming lead-bearing 
copper-alloy scrap for re-use. The research investi- 
gations relating to conservation and substitution and 
processing comprised an investigation to develop 
heat treatments for the National Emergency steels so 
that these steels could be utilized fully in ordnance 
materiel, a study of the hardenability of cast alloy 
steels which provided data of wide applicability in 
the utilization of alloy steels to attain high strength 
and toughness, and an investigation of the accept- 
ance tests for plain carbon steel forgings in an at- 
tempt to provide information of value in the prep- 
aration of specifications for ordnance forgings. 



I* 4 


«cl 




H t *4 

a 

- ^ P . 








.1 

* • 


I i 






4 r ^ ♦ 

' ■ '■ * 


■VI 1 

-> :_. 


0. _ • ■* 

» 

•\ . ' 

ypth ■" 
1 1 ■ 

r,p 

.' h% ‘iR 


' .►"‘-'a 

'W»# »’ ' 



f •* 

- V. 

» 

'"iisV 

T 

^ 1 



■ " - 

1 •■ , 1 

tv » * 


Im ..i * 


■. ■ ' jiifift Sili - * -1 

- • .-w 'fj 


‘ >, ’,trk' Ai;';*''' 1 ' ;i A; 

'4i ‘ >.' ..T; I ,■ ^ .'„■ 

• t; ,• .i -vli.n;' • , ' •> ,l - 


fc * 4 ^^ .* 4 W ’•J 


I 


-v^aUfk^K' '-’ • 11-' 

.3? ••*' ! • l*vl 




“Vit 




hk' i 



M 


.i 

*>▼ . 



''-W' 

» rH I'l 

’ -■, 'it^VkU: 


Chapter 1 

AIRCRAFT MATERIALS 


J » INTRODUCTION 

T he greater part of the NDRC work on aircraft 
materials was concerned with studies of the use 
of aluminum and magnesium alloys, principally in 
sheet form. When the aircraft production program 
was announced early in 1942, it was obvious that, 
in order to secure the most effective use of the then 
commercially available materials, it would be neces- 
sary to secure fundamental information on their 
properties both in service and during processing. 
The program of this part of the work of Division 
18 was organized to secure this information as 
quickly as possible. At the same time, projects were 
established to investigate the use of the beryllium- 
aluminum alloys for aircraft engine parts, the use 
of substitute materials for aircraft control cables, 
and the use of mechanical means for the improve- 
ment of the properties of aircraft materials by sur- 
face pre treatments. The results of this latter proj- 
ect, as the successful use of the surface pretreatment 
was demonstrated, was applied widely by both the 
Army and Navy and by their suppliers for many 
ordnance and naval applications other than air- 
craft. All this work was coordinated with the work 
of the National Advisory Committee for Aero- 
nautics and the Office of Production Research and 
Development of the War Production Board which 
were supporting extensive research programs in 
the field of light alloys. 

12 ALUMINUM ALLOYS 

*•2 * Preliminary Surveys 

Before planning a detailed experimental attack on 
a suggested problem, a preliminary survey usually 
was made by the War Metallurgy Committee, not 
only of the literature but also of unpublished infor- 
mation which normally would not have been avail- 
able but which, in the spirit of cooperation engen- 
dered by the war emergency, was freely supplied by 
industry. Such compilations of available data on 
aluminum alloys included Survey Project SP-17^ 

aSP numbers and NRC numbers refer to the Division 18 
project numbers. Listings of the titles of these with contractual 
information are presented in Appendix G and Appendix F, 
respectively. 


(NA-119),*^ The Effect of Impurities in Aluminum 
Alloys,^ SP-18, Fatigue and Impact Character- 
istics and Notch Effect in Tension of Artificially- 
Aged Aluminum Alloys;^ and SP-15 (NA-137), 
High-Temperature Properties of Light Alloys.® '^ 
The problems involved in the use of aluminum 
and magnesium alloys at elevated temperatures be- 
came more pressing late in World War II, and ex- 
perimental work on them was taken up under 
NACA and the Army Air Forces’ sponsorship as 
NDRC was in the process of bringing its research 
program to a close. 

1.2.2 FORMING OF ALUMINUM 
ALLOY SHEET 

The aircraft industry forms a vast variety of 
structural parts out of strong aluminum alloy sheet 
using a great variety of forming processes, tools, 
dies, and methods. These processes for forming 
aluminum alloy sheet vary from simple stretching, 
simple bending, etc., to highly complex ones in 
which the metal has to undergo plastic deformation 
in many directions, is thinned down in some places, 
thickened in others, and subjected to various 
stresses in the operations. These processes have 
often been empirically worked out for commer- 
cial material in a condition of high plasticity, 
greater strength being later given to the formed 
part by suitable heat treatment. 

However, still stronger parts can be made by 
forming cold-rolled sheet or preheat-treated sheet. 
Moreover, several stronger alloys, each with dif- 
ferent cold rolling and heat treating characteristics, 
have become available recently, and no one knows 
when still further strides will be made along the 
path of providing still stronger alloys. As fast as the 
stronger alloys become available and enough is 
known about their uniformity and reliability to 
justify their use, the aircraft designer wants to 
specify their use. The production engineer then 
must form them and is confronted with the fact 
that the stronger alloys are, as a rule, less ductile 
than those he has been forming heretofore. He then 

b Numbers in parentheses refer to the Armed Service control 
numbers. The Armed Service titles of these as well as the 
Division 18 projects pertaining to each are listed in Appendix E. 


CONFIDENTIAL 


11 


12 


AIRCRAFT MATERIALS 


has to find out whether his previous processes, 
methods, tools, dies, etc., will serve or whether they 
must be modified. He may find that some odd- 
shaped part wanted by the designer cannot be made 
at all from the new alloy, in which case there must 
be time out for redesign. When a new part is made 
in the shop, dies are made for it. If the new alloy 
breaks instead of forming properly, or springs back 
more or less than was anticipated, the dies have to 
be remade. 

Predetermination of the suitability of a given 
alloy or a given lot of an alloy for plastic forming, 
or of the applicability of a given process and tech- 
nique for forming a new part from a known alloy 
would be a godsend. 

Survey of Available Information on 
Fabricating Aluminum Alloys 

To collect and correlate the information avail- 
able on the forming of aluminum alloys, Project 
NRC-43 (NA-126), Correlation of Information 
Available on the Fabrication of Aluminum Alloys, 
was established at the Case School of Applied 
Science in January 1943. An exhaustive survey of 
plant practice showed many gaps in the fundamen- 
tal knowledge necessary for the effective use of 
these alloys. Therefore, at a later date, the project 
was extended to permit investigation of the more 
important forming operations in the laboratory. 

The initial objective of this project was to as- 
semble and to correlate all the available informa- 
tion concerning the materials and methods used in 
typical and critically forming parts so that the 
“know-how” could be made more readily available 
to parts producers, particularly the sub-contractors 
who were new to this work. 

A group of field engineers gathered all the specific 
information in the aircraft plants on materials used, 
each step of fabrication, kinds of dies, machines, 
lubricants, speeds, treatments, rejections, etc. This 
information was then broken down and correlated. 

A system of classification, which was primarily 
dependent on the geometry of the finished part, 
was evolved. However, many parts of essentially 
the same geometry may be made in several ways on 
different equipment. Also, parts which at first ap- 
pear to be essentially alike may prove to be suf- 
ficiently different in detail to cause them to have 
separate classifications and different fabrication 
methods. The classification consists of the follow- 
ing parts: 


I Singly curved parts. 

II Curved channels. 

III Contoured fianged parts. 

IV Double curvature smoothly contoured parts. 
V Deep recessed parts. 

VI Shallow recessed parts. 

VII Minor forming features. 

VIII Tubing. 

Over 100 types of parts were covered in detail, 
and the correlations show that several noteworthy 
conclusions can be drawn concerning: 

1. Preferred forming method for each type of 
part. 

2. Preferential use of one- or two-step forming. 

3. Comparison of different methods on similar 
parts. 

4. Preferred material for particular types of parts. 

5. Maximum strains during forming. 

6. Some engineering analysis of several forming 
operations. 

Because of the nature of this phase of the work, 
essentially a survey to find and report facts, it is not 
feasible to attempt a summary of the results other 
than to state that the volumes of reports provide a 
veritable library of forming information and have 
proved useful to both the engineering and the shop 
personnel. The following titles of these reports in- 
dicate their scope: 

Section I, Classification and Analysis of the Form- 
ing of Various Parts, Volumes I* and II.^ 

Section II, Examples of Fabricating Individual 
Parts, Volumes I^*^ and II. 

Section III, Summary, Contents, and Index of 
Sections I and Z/.^- 

To supplement its series of publications on pro- 
duction methods, the Production Aids Unit of the 
Bureau of Aeronautics, Navy Department, repub- 
lished these reports for wide distribution to aircraft 
fabricators. 

Properties of New Aluminum Alloys 

The initial results of the work emphasized also 
the need for information on the forming limits, 
properties, etc. Consequently the second phase of 
work was, at the request of the aircraft industry, 
centered on the new high-strength alloys. The ac- 
cumulated data are given in Section IV of the series 
of reports on the project which cover 24S-T8 sheet,^^ 
24S-T8 extrusions,!^ R-301 sheet,!^ XA75S sheet,!^ 
and 75S sheet.^^ Specific information is grouped 
under several headings for each alloy, these includ- 


CONFIDENTIAL 


ALUMINUM ALLOYS 


13 


ing (1) Mechanical Properties— Metallurgical Rela- 
tions, (2) Mechanical Properties— Design Data, (3) 
Physical and Chemical Properties, (4) Production- 
Forming, (5) Production— Other than Forming, (6) 
Corrosion and Surface Treatment, and (7) Bibli- 
ography and Additional Pertinent Information. 

This survey of properties of new aluminum al- 
loys relates to alloys of higher static yield strength 
and lower ductility than those in past use and still 
in large current use. Therefore, the corrosion, stress- 
corrosion, fatigue, notched fatigue, and corrosion 
fatigue behaviors are discussed where the data were 
available. Since the strong alloys can be, and almost 
universally are, clad with a corrosion-preventing 
layer of pure, or nearly pure, aluminum, major 
corrosion troubles appear to be preventable. 

The fatigue, and especially the notched fatigue, 
behaviors are insufficiently known. There is evi- 
dence that in some of the new alloys fatigue resis- 
tance is not better than that of the alloys used 
previously, although static strength is materially 
increased. This means that the service of aircraft 
parts needs to be examined to see whether a de- 
sign aimed to utilize the improved static strength 
neglects the possibility that fatigue failure will 
occur. If so, design should be on a fatigue basis, 
and the apparent virtues of some of the “strong” 
alloys might prove an illusion. Extensive fatigue 
and notched fatigue testing to establish which of 
the alloys afford the best compromise between static 
and fatigue strengths is in order, as is the refine- 
ment of design to avoid stress concentrations, the 
absence of which is not particularly material from 
the static point of view but very important from the 
fatigue point of view. In this way the use of the stat- 
ically strong alloys without overtaxing their limited 
ability to resist fatigue can be further developed. 

The series of reports on properties of new alu- 
minum alloys serves as a detailed handbook for 
engineers and shopmen, collecting the known in- 
formation pertinent to the application and use of 
these alloys for aircraft structural components. Be- 
cause of the nature and magnitude of this work, 
it serves as a ready cross reference for either the 
comparison of materials or the selection of a suit- 
able material for a particular application. 

Formability Investigations and Development of 
Test Methods 

The third phase of this project was concerned 
with laboratory studies of the actual formability of 


several aluminum alloys used in aircraft construc- 
tion. This involves fundamental considerations of 
the plastic flow of these materials under widely 
varying stress-strain conditions, particularly with 
respect to the more complex stresses, and with 
strain gradients. 

Beginning with the study of simple bends and 
the allied operations of stretching, both of which 
subject a uniform and symmetrical metal section to 
a combined tensile load and bending moment act- 
ing in the plane of symmetry of the cross section, 
the first step in the procedure is the accurate analy- 
sis of the stress conditions existing throughout a 
given operation and the correlation of this with the 
strains attained. Thus, when the exact conditions 
are formulated mathematically and checked practi- 
cally on special equipment, the results should pro- 
vide a basic engineering tool enabling the predic- 
tion of formability. 

In the initial experimental phase of the work, 
preliminary tests and some theoretical analyses of 
the various factors of the problem revealed that 
the relations between the external forces and gross 
movements on one hand and the internal stresses 
and strains on the other were extremely complex 
and that there were numerous factors exerting a 
definite influence on the maximum stretch of the 
tension fiber at the forming limit. FMr example, it 
is generally recognized that a strip or bulky section 
of the aluminum alloy 24S-0 can be bent to a very 
small radius, with a local stretch of the order of 
100 per cent, while on a thin-walled sheet section, 
such as an angle with the outer leg in tension, the 
web or the flange will fail when a stretch exceeding 
20 to 30 per cent is attempted. The numerous vari- 
ables were studied and attempts were made to out- 
line a series of tests in which only one or two vari- 
ables would be involved in order to determine the 
relative importance of each. The problem of thus 
limiting the variables “taxed the ingenuity of the 
investigators to the limit. They found it rather in- 
triguing that visualizing the fundamental relations 
of an apparently simple group of forming opera- 
tions clearly exceeded their capacity.’’^^^ 

The reports covering the experimental phase of 
this project. Section V, are as follows: 

Part I, General Introduction.^^^ 

Part II, Effects of Non-Uniform Stresses and 
Strains.'^^^ 

Part III, Stretch Forming of Angles with the 
Outer Leg In Tension.^’^ 


CONFIDENTIAL 


14 


AIRCRAFT MATERIALS 


Part IV, Fundamentals of Pure Bending of an 
Ideal Plastic Metal under Conditions of Plane 
S tress. 

Part V, Simple Bending of Rectangular Shapes 
by Means of Dies.^^ 

Part VI, Stretching of Rectangular Bars.^^ 

Part VII, Experimental Strain Analysis of Bent 
Rectangular Shapes.-^ 

Part VIII, Combined Bending and Tension of 
Rectangular Bars.^- 

Part IX, Bending of T-Sections.^^ 

The results of this comprehensive investigation 
were useful in the engineering and production of 
aircraft parts. While such information apparently 
is of primary significance to the engineer and de- 
signer, it has two very practical potentialities in 
the shop: (1) to predict formability limits of the 
given material, and (2) to apply this toward the 
engineering of forming dies. These objectives, how- 
ever, were not attained, since a simple method or 
methods for evaluating formability in the shop 
were not yet developed when the project was ter- 
minated in September 1945 because of the demobil- 
ization of NDRC. 

Related projects carried out under War Metal- 
lurgy Committee supervision, but classed as process 
projects and hence under WPB rather than NDRC 
auspices, were NRC-547, Hot Forming of Aluminum 
Alloy Parts, and NRC-548, Forming Properties of 
Aluminum Alloy Sheet at Elevated Tempera- 
tures.^ Since the stronger aluminum alloys are less 
amenable to cold forming than the weaker ones, 
and, since operating at somewhat elevated temper- 
ature greatly facilitates the forming of magnesium 
(see Section 1.3.5), it was logical to examine the 
response of the strong aluminum alloys to elevated- 
temperature forming. They were found to respond 
excellently. Indeed, at 400 to 450 F, the strong 75S 
aluminum alloy forms as readily as does soft 24S-0 
at room temperature. Many of the techniques de- 
veloped for magnesium alloys discussed later in this 
report should be applicable to the forming of alu- 
minum alloys. Hot forming of the strong aluminum 
alloys is being utilized in commercial shop practice. 

Supplementary to the work on the forming of 
aluminum alloys. Projects NRC-51 (NA-149) and 
NRC-52 (NA-150), Plastic Flow of Aluminum Air- 
craft Sheets under Combined Loads, were estab- 
lished at Carnegie Institute of Technology and 
Pennsylvania State College to secure information 
on certain limiting properties of these materials. 


Predetermination of ability for plastic forming 
is no easy matter, as is evidenced by experience in 
attempting to evaluate the deep-drawing steels. 
However, it does seem possible to acquire enough 
understanding of the fundamentals of plastic de- 
formation and of forming processes to decrease ap- 
preciably the amount of cut and try necessary, 
even though considerable must remain. 

The first approximation to a criterion of ability 
for plastic forming, and the one on which the 
engineer has to rely in the absence of better infor- 
mation, is the elongation determined by the ordi- 
nary tension test. However, some alloys, quite 
ductile by this criterion, will not stand much plastic 
deformation of certain types, while other less duc- 
tile ones will stand an astonishing amount. 

In most types of plastic forming, the metal is 
under biaxial stress, not uniaxial as in the tension 
test. Biaxial stress can be produced by pulling on 
the ends of a hollow cylinder while it is simultane- 
ously being stressed by internal hydraulic pressure, 
but this method is not applicable to sheet. 

The initial phase of the research program was the 
development of a series of laboratory tests capable 
of evaluating those plastic properties of importance 
in sheet metal forming operations. Particular em- 
phasis was placed on the plastic behavior of sheet 
metals under a wide variety of strain combinations. 
This resulted in the development of several tests, 
which in combination yield a great deal of useful 
information concerning the formability of a par- 
ticular material. These tests are as follows: 

Circular Hydraulic Bulge Test.-"^ A bulge method 
was developed in which a round or elliptical bulge 
or bubble is blown by hydraulic pressure from a 
sheet anchored at the periphery. Previously, a cross- 
hatched grid is placed on the sheet by photographic 
methods. As the bulge grows, the distortion of the 
grid is measured and the limiting deformation at 
fracture is noted. From these data and from the 
thickness at the places where uniform deformation, 
not necking down at fracture, has occurred, the 
stress can be calculated. This test had been used to 
some extent previously to study the ductility of 
sheet materials, but it was not well understood. In 
this investigation it was adapted to the study of 
stress-strain relationships in the plastic range and 
used to obtain stress curves under balanced biaxial 
tension, the state of stress being set up in the dome 
of a circular hydraulically formed bulge. 

Elliptical Hydraulic Bulge Test.-^ This test is a 


CONFIDENTIAL 


ALUMINUM ALLOYS 


15 


modification of the circular hydraulic bulge test. 
By altering the shape of the opening over which 
the bulge is blown from circular to elliptical, it is 
possible to set biaxial tensile strains, the ratio of 
which depends on the ellipticity of the opening. 
Use of the elliptical opening provides strain ratios 
comparable to those obtained in many practical 
forming operations. 

Microcompression Test.-^ To overcome the in- 
trinsic difficulties in compression testing of sheet 
materials, namely, the tendency for the ordinary 
specimen to buckle, a test was designed in which 
a specimen 0.04 in. by 0.04 in. by 0.12 in. is em- 
ployed. This test permits the stress-strain curves in 
compression to be determined for sheet materials 
of 0.040 in. thickness. 

Microtension Testr^ This test was developed 
primarily to check against size effect in the micro- 
compression test and utilizes a specimen of 0.04 in. 
by 0.04 in. corresponding to that of the microcom- 
pression specimen. It was possible to demonstrate 
by means of this test that size effect is absent in the 
microcompression test described above for commer- 
cial aluminum aircraft sheet. In the course of de- 
veloping these tests, a study was made of the stress- 
strain relationship for Alclad 24S-0 and 24S-T sheet 
under combined stresses. It was found that these 
materials obey a generalized stress-strain relation- 
ship in the plastic range. 

Direct Tension Testsr^ In addition to these tests, 
two direct tension tests were developed which pro- 
vide complementary information to that obtained 
in the above tests. In those types of plastic flow 
where simple stretching of wide sheet is concerned, 
the uniform stretch, before necking begins, is a 
criterion of behavior. In other types of flow, such 
as bending over a sharp radius, the local deforma- 
tion over a very minute gage length, which occurs 
during the necking process, is the criterion. The 
standard ASTM tensile specimen for sheet does 
not distinguish between these two types of flow. 
The uniform stretch is hampered by the proximity 
of the wider grips (the piece is not long enough), 
and the local deformation occurs over too great a 
length (the piece is too long). To separate these 
factors, a long specimen 2 in. wide by 12 in. long 
in the gage length and a short specimen 12 in. wide 
by 1 in. long were used. The first specimen yields 
data representative of that obtained when stretch- 
ing over long gage lengths, and the second, data 
representative of that obtained when stretching un- 


der conditions of severe lateral restraint. Tests us- 
ing these two types of specimens were made for 
Alclad 24S-0 and 24S-T, and flow curves in simple 
tension were determined for these materials. 

When the series of tests just described became 
available, it was deemed advisable to apply the 
tests to a study of the ductility at room temperature 
of the important aluminum sheet metal alloys. This 
study was carried out for the following materials: 
24S-0, 24S-T, 24S-RT, 24S-T81, 24S-T86, 75S-0, 
75S-T, R301-0, R301-W, R301-T. All sheets tested 
were 0.04 in. thick and in the clad condition. As 
a supplementary investigation, the effect of aging 
at room temperature on the properties of 75S in 
the circular bulge test was studied. 

The detailed results of this series of tests are 
covered in Parts II and III of the final report for 
the project.27 . 28 Certain regularities were observed 
which can be summarized as follows: 

1. Uniform elongation is strongly dependent 
upon the method of loading. Loading in the cir- 
cular hydraulic bulge test favors high uniform 
elongations in the annealed materials in which it 
is possible for unstable plastic flow to occur. 

2. In the circular bulge test, the behavior of the 
aged materials where instability does not occur 
varies with the stress-strain characteristics of the 
material being tested. For very high ratios of yield 
strength to tensile strength, the uniform elongation 
in the circular bulge test is considerably greater 
than in simple tension. On the other hand, for 
lower yield strength-tensile strength ratios, the uni- 
form elongation is about the same or somewhat less 
than in simple tension. 

3. For annealed materials, the uniform elonga- 
tion in the circular bulge test is always greater than 
in the elliptical bulge test. In the heat-treated 
materials, this difference is still present but is much 
less pronounced and, in some cases, the results from 
the tests are quite similar. 

4. The local reduction of area for the annealed 
tension tests is unaffected by lateral restraints im- 
posed in the wide specimen. In the heat-treated 
materials, however, the reduction of area is con- 
siderably lower in the wide test than in the narrow. 

5. It was found that 75S-W could not be formed 
satisfactorily in the circular bulge test because 
of the strong tendency for the formation of strain 
markings similar to Liider’s lines which lead to 
premature failures. 

In order to provide a more rational basis for the 


CONFIDENTIAL 


16 


AIRCRAFT MATERIALS 


interpretation and understanding of these results, a 
mathematical analysis of some of the conditions 
leading to unstable plastic flow and rupture was 
carried out. The role of these factors in establishing 
forming limits is discussed in Part IV of the final 
report on the project.^^ 

Inasmuch as the most profitable application of 
data on forming limits can be realized only if some 
previous knowledge of the critical strains arising 
in forming a part of given design is available, con- 
siderable attention was devoted to this problem. 
Analyses were developed for the strain distribution 
in a circular hydraulically formed bulge and an 
elliptical hydraulically formed bulge, these parts 
representing pure stretching. The problem of com- 
bined stretching and drawing was next considered 
and an analysis derived for a circular cylindrical 
cup with a spherical bottom.^^ Good agreement 
with observed strain distributions was obtained 
with all these solutions. 

These methods allow a better evaluation of the 
plastic behavior of different aluminum alloys in 
different conditions of cold work or heat treatment. 
With a background of experience in the forma- 
bility of, and die design for forming, a few com- 
mercial alloys, the way in which a new alloy will 
behave under conventional forming methods and 
existing dies could be predicted approximately 
from the long and short tensile specimens and the 
bulge test data. 

However, if a new part has to be made, even 
these data on forming limits may be inadequate, 
and the best guide will be the “know-how” accumu- 
lated from experience with more or less analogous 
parts with similar types of deformation. 

Casting of Aluminum-Beryllium 
Alloys 

A decade or so ago, tests of some small forgings 
and castings of aluminum alloys containing 20 to 
35 per cent of beryllium indicated interesting prop- 
erties, and rather elaborate plans, which never 
materialized, were made for relatively large-scale 
production of sheet and forgings. Sporadic experi- 
ments were carried on thereafter, both by producers 
of beryllium and by producers of aluminum. A 
particular aim, desired for the aircraft service, was 
the production of sound alloys of this type, either 
cast or forged in a size suitable for pistons of air- 


craft engines. Considerable commercial effort along 
this line produced nothing but a succession of fail- 
ures and a belief among those who had worked on 
the problem that the alloys were not amenable to 
processing in the size required. Others were not 
convinced of this and argued that there was a 
possible chance that more exhaustive experimental 
work would show how processing might be accom- 
plished. 

Because the properties that would be secured if 
the alloys could be processed were so attractive, 
the Bureau of Aeronautics, Navy Department, de- 
cided to explore this chance. Project NRC-7 
(NA-100) (AC-4), Beryllium- Aluminum Alloys for 
Engine Parts, therefore was established at the 
National Bureau of Standards, everyone concerned 
being advised that the prospects of success were 
very remote. 

Much careful work, even trying out methods such 
as not only melting in vacuum but even pouring 
in vacuum, led to the conclusion that the com- 
mercial investigators were quite correct in their 
opinions that the alloys are not amenable to proc- 
essing. Moreover, the reason for this was estab- 
lished as being the long range between the 
beginning and end of solidification which prevents 
adequate feeding and, therefore, on first freezing, 
produces a mass full of shrinkage voids and a 
matrix that will not withstand forging to close the 
voids. Only the casting of a very thin layer followed 
by another very thin layer, and so on, offered any 
possibilities, and no technique was found by which 
this solution could be utilized successfully. Various 
alloying additions were tried with the idea of trying 
to reduce the long freezing range, but none were 
successful.31 

It became obvious that the chances of overcom- 
ing the difficulties were so small and so great an 
amount of work would be required to produce 
sound masses of the size wanted, if it were ever 
possible to produce them, that the effort would be 
far better spent on more practical war problems. 
The project, therefore, was terminated. 

1.2.4 Needs for Research on Aluminum 
Alloys 

Late in World War II, at the request of the 
Committee on Materials Research Coordination of 
NACA, a survey was undertaken to determine the 


CONFIDENTIAL 


MAGNESIUM ALLOYS 


17 


research needs of the aircraft producers with re- 
spect to aluminum alloys. Although Project SP-30, 
Suggested Research on Aluminum Alloys from 
Members of the Aircraft Industry, was completed 
after the close of the war, the report^^ outlines the 
problems that still existed. 

1.2.5 Indexing of Division 18 Reports 
on Aluminum Alloys 

An indexes of the Division 18 reports on alumi- 
num alloys was prepared by the Research Informa- 
tion Division of the War Metallurgy Committee. It 
gives a subject list of the various projects with the 
reports issued on each, a brief abstract of each report, 
and a subject index of the reports. It is believed that 
this index will enhance the usefulness of the many 
reports on the subject. 

13 MAGNESIUM ALLOYS 

Introduction 

The very slight commercial use so far made of 
magnesium alloy sheet naturally portends a lack of 
knowledge of its possibilities and limitations to a 
degree even greater than exists for the more widely 
used aluminum alloys. Moreover, magnesium has 
problems of its own not present in aluminum. The 
magnesium crystal is not cubic but hexagonal, and 
this involves the possibility of directional differ- 
ences in magnesium sheet. Also, the hexagonal crys- 
tal is less suited to plastic deformation than is the 
cubic crystal, so that magnesium alloys as a class 
cannot be subjected to severe plastic deformation 
at ordinary temperatures but must be warmed con- 
siderably in order to stand even a reasonable 
amount of such deformation. 

While it may be that the corrodibility of magne- 
sium alloys has been overemphasized, some do 
corrode badly under certain circumstances, and 
attempts to clad them with a protective metal layer 
analogous to that used on clad aluminum alloys 
have not been commercially successful. The possi- 
bility of failure of certain magnesium alloys as a re- 
sult of stress corrosion has come recently to the fore. 

Current magnesium alloys are rather notch sen- 
sitive, and their static and fatigue strengths are, 
even on a strength-weight basis, little better, if any. 


than those of aluminum alloys. 

Thus, a multiplicity of unknown or inadequately 
known factors must be taken into account when 
magnesium sheet is proposed for aircraft use. 

However, enough possible aircraft uses were in 
sight in which it might be at least a competitor 
with aluminum to warrant a comprehensive study. 
Moreover, the existence of adequate production 
facilities for making the metal was an added spur 
toward obtaining a true evaluation of its proper 
position as an engineering material. 

In mid- 1942 two projects were established to 
investigate the properties of commercial magnesium 
alloys— one dealing with mechanical properties and 
heat treatment, the other, with fatigue properties. 
Subsequently the program was extended to include 
studies of the formability and deformation charac- 
teristics of magnesium alloys. In March 1943 ii 
became apparent to the members of the War Metal- 
lurgy Committee Project Committees for these 
projects that an independent and comprehensive 
study of the stress corrosion of commercial magne 
slum alloy sheet should be made. As a result of this 
study, a project was established to develop new fab 
rication methods to minimize stress corrosion in 
commercial alloys and to develop new alloys less 
susceptible to stress corrosion. 

1.3.2 Mechanical Properties of Magnesium 
Alloys 

At the request of the aircraft industry, the War 
Metallurgy Committee initiated the establishment 
of Project NRC-21, Properties and Heat Treatment 
of Magnesium Alloys, at the University of Cali- 
fornia. Subsequently, the Bureau of Aeronautics, 
Navy Department, endorsed this project and ac- 
tively cooperated in its prosecution under their 
control number NA-144. The objectives of this in- 
vestigation were the determination of the effects 
of size and notches on the mechanical properties 
of commercial magnesium alloys for aircraft and 
combat vehicle use, the evaluation of the damping 
properties of these alloys, and an investigation of 
heat treating processes with a view to the develop- 
ment of superior properties for these alloys. After 
the first year of study, the program was extended 
at the suggestion of the producers of magnesium 
to include studies of the notch sensitivity of new 
alloys in sheet, strip, cast, and extruded forms. 


CONFIDENTIAL 


18 


AIRCRAFT MATERIALS 


Effect of Size Upon Tensile Properties 
OF Specimens of Magnesium Alloy Sheet^^ 

Four magnesium alloys (both the hard-rolled and 
annealed 61/2% Al, Zn alloys and li/2% Mn 

alloys) were investigated for the effect of size on the 
tensile properties of sheet. In general, the material 
investigated was within the manufacturer’s stated 
specifications. 

The tensile strength, yield, and percentage of 
elongation in a 2-in. gage length show very little 
size effect. The reduction at the fracture section 
reveals that the percentage of reduction in area 
and the true breaking stress decrease as the width 
increases. From the nominal tensile properties ob- 
tained, it does not appear that a true size effect 
exists for tlie materials investigated. However, nar- 
row specimens exhibit a greater percentage of re- 
duction in width than wide specimens, which 
indicates that greater local necking down occurs 
in the narrow specimens. The percentage of elonga- 
tion in 2 in. does not show any definite variation 
with size. 

The difficulties encountered in industrial prac- 
tices are probably associated more with gripping 
and load application than with a size effect of the 
material. 

Notch Sensitivity of Magnesium Alloys^^’^^^ 

In the order of increasing sensitivity to a reamed 
hole, the alloys tested were hard-rolled li/2% Mn al- 
loy, annealed U/2% Mn alloy, hard-rolled 61^^% Al, 
Zn alloy, 24 S-T aluminum alloy, Alclad 24 S- 1 ’ 
aluminum alloy, and annealed 614% Al, Zn 

magnesium alloy. The annealed and more ductile 
magnesium alloys are more notch sensitive than the 
hard-rolled and less ductile alloys of the same com- 
position. For li/2% Mn alloys, the thin sheets are 
more notch sensitive than the thick sheets, but for 
the 61/2% Al, Zn alloys, the notch sensitivity 

is invariant with sheet thickness. A large increase 
in sensitivity to the notch occurs as the width of 
the specimen increases for constant form factor for 
all alloys tested for this effect (both the hard-rolled 
and annealed 61/2% Al, Zn alloys and 11/2% Mn 
alloys). The tensile strengths of both notched and 
unnotched specimens, based on both original and 
final cross section area, are considerably greater at 
—318 F than at room temperature. For a condition 
of very small ductility (annealed 61/2% Zn, Al 


alloy at —318 F, elongation about 5 per cent, and 
hard-rolled 61/2 7 ^ Zn, 34% Al alloy at -318 F, elon- 
gation about 1 to 2 per cent) the stress distribution 
in a notched specimen does not follow that pre- 
dicted by elastic theory but agrees in general with 
the distribution existing for a ductile material. 
Hence, only a very small amount of ductility is 
required to redistribute completely the stresses at 
the root of the notch. 

The notch efficiencies in tension for American 
Magnesium Corporation annealed and hard-rolled 
3 % Al, 1% Zn sheet alloys and the equivalent Dow- 
metal alloys were evaluated. The notch used 
throughout this investigation consisted of a single 
central hole in a tensile test specimen, and the 
notch efficiency was expressed as the ratio of the net 
average tensile strength notched divided by the ten- 
sile strength unnotched. As in previously reported 
investigations on other magnesium sheet alloys, it 
was found that the notch efficiency depended upon 
the ratio of hole diameter to specimen width for 
constant width specimens, and the notch efficiency 
depended upon specimen width when the ratio of 
hole diameter to specimen width was held constant. 
The hard-rolled alloys were practically insensitive 
to a notch except for the wider specimens which 
were investigated. The annealed alloys exhibited 
minimum notch efficiencies of about 0.90 for 1-in.- 
wide specimens at ratios of hole diameter to speci- 
men width of about 0.125 in. As the specimen 
width increased from 1 inch to 6 inches, the notch 
efficiency was reduced from about 0.90 to about 
0 . 82 . These observations are in agreement with the 
general trends previously reported for other alloys. 

In general, variations in the procedure of pro- 
ducing the hole had little influence on the notch 
efficiency. Variations in drilling speeds and feeds 
had no influence on the notch efficiencies. Drilled 
and reamed holes presented only slightly superior 
notch efficiencies to those obtained by drilling 
alone. Other factors such as lubrication, drill design, 
and drill dullness were investigated. 

Difficulties owing to the formation of small 
cracks were encountered in punching holes in mag- 
nesium alloy sheet at atmospheric temperature. 
These difficulties were overcome by punching the 
magnesium alloy sheet at elevated temperatures. 
The optimum temperature at which the highest 
notch efficiency occurs is unique for each alloy. 
Complete data for the optimum punching temper- 


CONFIDENTIAL 


MAGNESIUM ALLOYS 


19 


atures, punch an die design, and clearance were ob- 
tained. Under the best combinations of conditions for 
punching, some alloys exhibited a higher notch effi- 
ciency for punched holes than for drilled holes. 

Standard dimpling procedures always resulted in 
cracking magnesium alloys when the operation was 
carried out at atmospheric temperatures. However, 
all of the standard magnesium alloys may be satis- 
factorily dimpled at elevated temperatures. The 
optimum temperature for dimpling as evaluated by 
the notch efficiency closely corresponds to the op- 
timum temperature for punching. Each alloy, there- 
fore, exhibits highest notch efficiencies when dimpled 
at the optimum temperature for that alloy. 

7'he sensitivity of magnesium alloys to scratches 
is of about the same order of magnitude as the sen- 
sitivity of 24S-T aluminum alloy, but it is greater 
than the sensitivity of Alclad 24S-T. 

The notch sensitivities of extrusions of four mag- 
nesium alloys ( 61 / 2 % Al, Zn alloy, li/^% Mn 
alloy, 8 i/^% Al, i/^% Zn alloy, and the 3% Al, 3% 
Zn alloy) in the “as received” condition were in- 
vestigated under conditions of axial and eccentric 
tensile stress. The notch sensitivities of extruded 
aluminum 24S-T and sand cast magnesium alloy, 
9% Al, 2% Zn, were studied for comparison. 

Extrusions of the 6 i/^% Al, Zn alloy, 8 i/^% 
Al, i/^% Zn alloy, and the 3% Al, 3% Zn alloy, like 
aluminum alloy 24S-T, displayed notch strengthen- 
ing under axial tension. The li/ 2 % alloy 

showed little notch effect, while the 9% Al, 2% 
Zn alloy showed reduction in strength under the 
notch. Notch sensitivity in the “as received” con- 
dition did not correlate with grain size, hardness, 
elongation in 2 in., stress-strain relationships, or 
any of the conventional tensile test data. 

Under eccentric stress, the strength of notched 
bars was reduced greatly. The order of notch sen- 
sitivity of the magnesium alloys studied, namely, 
61 / 2 % Al, 3^% Zn alloy, 3% Al, 3% Zn alloy, 81 / 2 % 
Al, 1 / 2 % Zn alloy, li/ 2 % Mn alloy and 9% Al, 2% 
Zn alloys in order of decreasing ratio of notched 
strength to unnotched strength, was the same in 
axial and eccentric tension. However, aluminum 
alloy 24S-T showed greater sensitivity to notches 
under small eccentricities of stress than the 61 / 2 % 
Al, Zn alloy, the 3% Al, 3% Zn alloy, and the 
Si/ 2 % Al, 1 / 2 % Zn alloy. In the “as received” condi- 
tion, the magnesium alloys are similar to aluminum 
alloy 24S-T in notch sensitivity. 


Within the limits of this investigation, prestretch- 
ing of extrusions of the 6 i/^% Al, Zn alloy, 

11 / 2 % Mn alloy, and 8 i/^% Al, 1 / 2 % Zn alloy re- 
sulted in increased ratios of notched strength to 
unnotched strength. 

While the 8 i/^% Al, i/^% Zn alloy extrusions in 
the “as received” and in the solution heat-treated 
conditions showed notch strengthening, these ex- 
trusions showed reduction in notched strength on 
aging. For this alloy aged “as received,” the ratio 
of strength notched to strength unnotched was 
about 0.83, but when aged after solution heat treat- 
ment, this ratio fell to 0.50. In the heat treatment 
study, changes in microstructure were found to ac- 
company changes in tensile notch sensitivity. 

Damping Capacity of Magnesium Alloys^^ 

The mean specific damping capacities of three 
magnesium-base extrusions, nine magnesium-base 
sand castings, and seven aluminum-base sand and 
permanent mold castings were investigated. These 
investigations indicated that magnesium alloys have 
rather high damping capacities which may be use- 
ful in absorbing energy in freely vibrating systems. 
These capacities were evaluated and compared with 
those of aluminum alloys. The high damping capa- 
city of magnesium was correlated with the forma- 
tion of twins in the material. 

Heat Treatment of Magnesium Alloys^s 

The solution heat treatment and aging of the 
9% Al, 2% Zn alloy were investigated. Solution 
temperatures of 770 F to 775 F were found to give 
the best results. Local fusion occurs in this tempera- 
ture range but does not become harmful unless 
temperatures are higher. Preheating does not pre- 
vent local fusion and is of no benefit except in 
overheated specimens. Overheating may be detected 
by the presence of grain boundary voids in polished 
specimens. Some heats which manifest coarse grain 
sizes, presumably as a result of variations in 
foundry practice, require higher temperatures or 
longer times for solution treatment. 

Direct quenching into hot or cold water from the 
solution temperature results in cracking, probably 
because of hot shortness. If bars are cooled to tem- 
peratures between 715 and 750 F before quenching, 
cracking is avoided. This procedure has been called 
a modified quench. Properties of bars subjected to 
such a treatment are about the same as those of 


CONFIDENTIAL 


20 


AIRCRAFT MATERIALS 


bars cooled in air according to the commercial prac- 
tice. After aging, however, quenched bars develop 
10 per cent greater tensile strength and yield 
strength than bars cooled in air. To develop maxi- 
mum properties a high degree of solution must be 
obtained before aging. Coarse-grained castings re- 
quire special care. 

Two modes of precipitation of the beta phase 
have been observed, a lamellar type growing from 
nuclei in the grain boundaries and a general pre- 
cipitation in crystallographic planes throughout the 
grains. The mode of precipitation does not vary 
with aging temperature. There are indications that 
recrystallization of the matrix accompanies lamellar 
precipitation and that the strengthening effect of 
such precipitation is small. Recrystallization does 
not attend general precipitation, which is mainly 
responsible for age hardening. Less lamellar preci- 
pitation results from the aging of bars quenched in 
hot water than from bars cooled in air or quenched 
in cold water previous to aging. This treatment 
minimizes the extent of lamellar precipitation and 
yields the best tensile properties. It is found that 
aging time may be considerably shortened, obtain- 
ing equivalent results, through substitution of 375 
F for the usual aging temperature of 350 F. A new 
heat treating schedule is recommended consisting 
of solution treatment, cooling of the furnace to 730 
F, quenching in boiling water, and aging for 4 to 
5 hours at 375 F. 

The data given in the reports cited in the fore- 
going discussion are of direct value to designers of 
aircraft and military equipment and it is believed 
that they will help to extend the use of light struc- 
tural alloys. 

It was evident in the work of this project that 
the control of grain size in magnesium castings is 
essential. Work on this, together with much other 
work on avoidance of microporosity so as to get 
sound castings and sound forging blanks, was car- 
ried on under War Metallurgy Committee super- 
vision, but, since these projects were classified as 
process research and came under OPRD rather than 
OSRD auspices, they are not summarized here. The 
OPRD projects were Project NRC-546, Cast Magne- 
sium Alloys and Existing Foundry Techniques and 
Practices, conducted by Battelle Memorial Institute, 
and Project NRC-550, Control of Grain Structure 
and Its Effect on Quality of Magnesium Alloy Cast- 
ings, conducted by the University of California. 


Other OPRD projects on the fabrication of mag- 
nesium were Project NRC-549, Machinability of 
Cast Magnesium and Magnesium Alloy Ingots, con- 
ducted by Battelle Memorial Institute, and Project 
NRC-552, Production and Properties of Mag- 
nesium Press and Hammer Forgings, conducted by 
the Wyman-Gordon Company. 

1.3.3 Fatigue Properties of Magnesium 
Alloys 

To complement the work on the investigation 
described above. Project NRC-22 (NA-145), Fatigue 
Properties of Magnesium Alloys and Structures, was 
established at Battelle Memorial Institute. The aim 
of this project was not only to determine the 
fatigue properties of commercial magnesium alloys 
but also to study the fatigue properties of welded 
and riveted structures fabricated from magnesium 
alloy sheet. The program was revised subsequently 
to include the obtaining of fatigue data on mate- 
rials supplied by Project NRC-67, Physical and 
Stress-Corrosion Properties of Magnesium Alloy 
Sheet, and Project NRC-68, Spot Welding of Mag- 
nesium Alloys. The first of these projects is discus- 
sed in this chapter of the report, while the latter is 
described in Section 6.1.4 on welding. Also included 
in the program was the further exploration of 
promising methods of joining magnesium and the 
obtaining of fatigue data on joints other than simple 
lap joints. 

Static notch sensitivity, discussed in Section 1.3.2, 
and stress-corrosion behavior, to be discussed in 
Section 1.3.4, tell little or nothing about notch sen- 
sitivity in fatigue or about corrosion fatigue. 

The unnotched fatigue behaviors of the strong 
(Al-Zn) magnesium alloys are very much alike, and 
in the annealed state these alloys are nearly as fa- 
tigue resistant as the hard-rolled. The li/ 2 % Mn 
alloy, hard-rolled, is superior to the other alloys at 
stresses that require more than 100,000 cycles for 
failure. 

With drilled rivet holes, the 3% Al, 1% Zn alloy 
is more notch sensitive than the 61 / 2 % Al, 

Zn alloy or the hard-rolled 1^2% Mn alloy. 
All are more notch sensitive in fatigue than in 
static tension. But if the rivet holes are filled with 
“scab” rivets, the fatigue strength rises close to that 
of a monoblock specimen. 


CONFIDENTIAL 


MAGNESIUM ALLOYS 


21 


Riveted lap joints failed in the sheet rather than 
through the holes. The fatigue values are not sim- 
ply related to the static values and differ with the 
ratio of static component to alternating component 
of the load, as well as with the alloy. The fatigue 
strength was much below that of monoblock speci- 
mens. Prediction of behavior, without test, would 
therefore be difficult. Spot-welded lap joints failed 
at or near the weld and the fatigue strength was 
very low, without much difference among the vari- 
ous alloys tested. 

Joints made by arc welding under helium (Heli- 
arc) were only slightly better in fatigue resistance 
than riveted joints in the 11 / 2 % alloy, but very 
much better in the 61 / 2 % Al, Zn alloy. Fatigue 
strengths of Cycle-Weld joints, made with an or- 
ganic adhesive, came close to the values for Heliarc 
welded joints in the 61 / 2 % Al, Zn alloy and 

were vastly superior in the li/ 2 % Mn alloy. The 
efficiency of a joint that was merely stuck together 
was striking, failure occurring in the metal rather 
than in the joint. However, similar joints made at 
a later date by the same firm which made the 
earlier Cycle-Weld joints were inferior, the joint 
separating. This difference probably related to the 
care taken or the neglect shown in cleaning the 
joint surfaces before applying the adhesive. The 
potentialities of a properly made adhesive joint 
are vast, and the method deserves intensive develop- 
ment. Of course, room temperature tests do not 
show how much such joints will behave at higher 
temperatures where some adhesives of this class tend 
to soften, or at low temperatures where most of 
them tend to become brittle. However, static tests 
show encouraging behavior of some adhesives un- 
der extremes of temperature. Once the technique 
of cleaning the metal and making the joints is un- 
der control, high- and low-temperature fatigue 
studies of these joints would be in order. 

Corrosion fatigue tests were made on monoblock, 
unnotched specimens, using the solution that was 
selected for static stress-corrosion testing in Project 
NRC-67, (described in Section 1.3.4) as well as 
other solutions. The specimens were allowed to cor- 
rode, stressed or unstressed, both before fatigue test- 
ing and simultaneously with fatigue testing. Natur- 
ally, corrosion increases the stress concentration 
and decreases the resistance to fatigue. Fatigue tests 
reveal the presence and effect of corrosion before 
corrosion is detectable by static tests. 


The heat treatments developed in Project NRC- 
67 (described in Section 1.3.4) to prevent static 
stress-corrosion cracking do not materially affect the 
fatigue or corrosion fatigue results, and thus the 
static improvement is achieved without harmful 
effects from the point of view of repeated stress. 
Heliarc-welded specimens appear no more sensitive 
to corrosion fatigue than monoblock specimens. 

Details of the experimental work and equipment 
used are given in three progress reports.^^’^^-^i 
Generalizations of the principal conclusions reached 
in the final reports'^-’^'^*^^ are as follows: 

1. An extension of fatigue data on the 61 / 2 % Al, 
Zn alloy sheet to negative ratios of minimum 

to maximum stress indicates that, for ratios as large 
as —0.5, values for the negative ratios fall on smooth 
curves obtained from positive ratios. 

2. Measured stress concentration factors for 
notches in the 61 / 2 % Al, Zn alloy are lower 
than those computed theoretically. The measured 
stress concentration factor depends on the mean 
load and is lower for high mean loads. It is prob- 
able that high mean loads produce some creep 
which relieves part of the stress concentration. 

3. Studies of the effect of precipitation heat treat- 

ments which were developed to combat static stress- 
corrosion on the fatigue strength of magnesium 
alloys show that such treatments have very little 
effect on the 61 / 2 % Al, Zn alloys. However, 

they lower the fatigue strength of the 3% Al, 1% 
Zn type alloys. These heat treatments do not appre- 
ciably alter the corrosion fatigue characteristics of 
the alloys, although they do affect the static stress- 
corrosion limit. 

4. Some tests which were conducted to find out 
whether unusually bad corrosion fatigue effects 
might be associated with Heliarc welds indicate 
that these welds do not affect the corrosion fatigue 
strength unfavorably. 

5. Cycle-Welded joints vary widely in strength, 
and the technique of making reproducible joints 
was not under control in the making of the second 
lot tested. 


Stress-Corrosion of Magnesium Alloys 

One of the greatest drawbacks to the use of mag- 
nesium alloy sheet materials was the failures of 
structures by fracture of the sheet through the 


CONFIDENTIAL 


AIRCRAFT MATERIALS 


99 


mechanism o£ stress-corrosion cracking. Consider- 
able concern was aroused by the observation that 
some commercial magnesium alloy sheet structures, 
under moderate stress and subjected only to atmos- 
pheric corrosion, cracked spontaneously. Some of 
the very striking observations were later found to be 
due to assembly methods that disregarded the limi- 
tations of magnesium, owing to unfamiliarity of 
workmen with the behavior of the material, but it 
was nevertheless shown that stress-corrosion crack- 
ing could occur. 

To bring out the vital problems and determine 
the research needs in the subject of stress-corrosion 
cracking of magnesium alloy sheet. Survey Project 
SP-12, An Investigation of the Present Status of 
Magnesium Alloy Sheet in the Aircraft Industry, 
was established in March 1943 by the War Metal- 
lurgy Committee at the suggestion of representatives 
of the aircraft manufacturers. This was an engineer- 
ing survey covering commercial information much 
of which was confidential company information on 
the limitations of magnesium alloy sheet.^^ 

The principal undesirable properties of magne- 
sium alloy sheet for aircraft construction were sus- 
ceptibility to stress-corrosion, low compressive yield 
strength, extreme notch sensitivity, wide variations 
between minimum specification values and those of 
the majority of the stock received, tendency for 
mechanical properties to become lower on cyclic 
loading, and anisotropy. With respect to these un- 
desirable properties, the 61 / 2 % Al, Zn alloy 

was the poorest and the li/ 2 % Mn alloy the best, 
with the 3% Al, 1% Zn alloy being intermediate. 
Unfortunately, the li/2% alloy has the lowest 
mechanical properties of all, although it is the best 
in most other respects. The British and the Ger- 
mans seemed to have solved their problems by us- 
ing alloys similar to the li/2% exclusively. 

However, there are no indications that they used 
magnesium alloy sheet for highly stressed primary 
aircraft structures. 

Of all the objections to the use of magnesium, 
its susceptibility to stress-corrosion cracking is the 
one that makes its use for critical parts question- 
able. Most of the other weaknesses can be overcome 
by design changes, but it appears that stress-corro- 
sion cannot be overcome by structural engineering 
techniques alone. 

The most probable theory for stress-corrosion 
cracking seemed to be that at ordinary tempera- 


tures stress favors the separation of material which 
would otherwise remain in solid solution. If this 
separated material, or precipitate, comes out on 
grain boundaries, it can be corroded away more 
readily, leaving a branching stress-raising void be- 
tween the external grains, at which cracking may 
start. If, by changing the composition, the material 
can be kept in solution or if it can be precipitated 
diffusely within the grains where corrosion cannot 
reach it, the material should be immune to stress- 
corrosion cracking. 

In an attempt to cope with the stress-corrosion 
problem. Project NRC-67 (NA-147), Physical and 
Stress-Corrosion Properties of Magnesium Alloy 
Sheet, was established at Rensselaer Polytechnic 
Institute in June 1943. The original objectives of 
the project were to study (1) the variations in the 
physical properties of available commercial alloy 
sheet with a view to reducing the spread in physi- 
cal properties which retard the adoption of this 
material by designers in the aircraft industry, (2) 
the effect of aluminum and zinc on the susceptibil- 
ity of the resultant alloys to stress-corrosion, (3) the 
effect of variations in aluminum and zinc content 
on the mechanical properties of sheet material and 
the possibilities of their improvement by heat treat- 
ment, and (4) new alloying additions and their 
effect on the mechanical properties and resistance 
to stress-corrosion. 

Obvious difficulties arose in the rapid correlation 
of the results of any selected laboratory test for 
propensity toward corrosion cracking and behavior 
under long-time atmospheric corrosion. This was 
handled by assuming that, if a laboratory test were 
made using some chemical solution which produced 
the same type of failure as had occurred in the at- 
mosphere and an alloy or a treatment found that 
would withstand stressing above normal design 
loads in such a solution without failure, that alloy 
or treatment would probably be immune in atmos- 
pheric service. It was recognized that the elapsed 
times for relatively early failures in such a test 
might not be commensurate with the probable life 
in actual service. Therefore, such test could not be 
interpreted quantitatively, though there should be 
some qualitative indication of how different vari- 
ables were influencing the tendency toward, or 
away from, stress-corrosion cracking. 

It was necessary, therefore, to make a compre- 
hensive study of methods for determining the re- 


CONFIDENTIAL 


MAGNESIUM ALLOVS 


23 


sistance to stress-corrosion and to correlate the 
results of each method. This resulted in the estab- 
lishment of laboratory procedures for investigating 
the problem of improving the physical and stress- 
corrosion properties. It was found that in cold- 
rolled commercial stock a stress relief anneal at 
350 F for 2 hours greatly mitigated corrosion crack- 
ing without seriously impairing other properties. 
Subsequently, cold rolling to about 20 to 30 per 
cent reduction followed by a 250 F stress-relieving 
treatment was found to produce metal with a mini- 
mum tendency toward stress-corrosion cracking and 
with mechanical properties at least as good as those 
produced by the earlier, conventional methods. 
This afforded a solution to what at first appeared 
a problem most difficult to solve.^® In addition to 
studying various heat treatments, rolling proced- 
ures, and combinations of the two, the effects of 
various surface treatments on stress-corrosion were 
also investigated.^^ These included anodic treat- 
ments, selenium treatment, dichromate treatment, 
and shot peening. 

The first phase of the studies of the development 
of alloys with improved mechanical properties and 
resistance to stress-corrosion involved investigating 
the effects of minor addition agents and minor varia- 
tions in melting practice on the properties of alloys 
of the 61 / 2 % Al, Zn and 5% Al, 1% Zn types. 
In this work, observations were made that agreed 
with those made under Project NRC-70, discussed 
in Section 1.3.6, as to the desirability of pure metal, 
that is, metal presumably free from oxide. Although 
improvements were made in the resistance to stress- 
corrosion of alloys of the 61 /^^% Al, Zn and 

5% Al, 1% Zn types, alloys with a new high level 
of mechanical properties were not developed. 

Studies were then started on the development of 
new alloy compositions with improved properties. 
This was approached by investigating precipitation 
hardening in alloys of widely varying compositions. 
The response to precipitation hardening treatment 
was evaluated through hardness tests. 

It was found that additions of Cd and Ce to- 
gether caused precipitation hardening and that ad- 
ditions of Ag to Mn-Al-Sn alloys improved precipi- 
tation hardening. Encouraging results were ob- 
tained with Mn-Zn and Mn-Zn-Zr alloys. This work 
was incomplete when the project was terminated 
in October 1945 in accordance with NDRC demob- 
ilization plans. It is being continued under a direct 


contact with the Materials Laboratory, ATSC, 
AAF, Wright Field. Research on the development 
of new magnesium alloys with improved properties 
is also being sponsored by the Bureau of Aeronau- 
tics, Navy Department. 

1.3.5 Forming of Magnesium Alloy Sheet 

Another obstacle to the use of magnesium alloy 
sheet in aircraft construction was the lack of knowl- 
edge of its forming properties. Owing to the very 
limited use of magnesium as a material of construc- 
tion and almost complete lack of experience in its 
use in fabricating aircraft, it was imperative that 
data be obtained as expeditiously as possible which 
would be of value to the designers and fabricators 
in determining the possibilities and limitations of 
these alloys. 

At the insistence of the aircraft industry, the War 
Metallurgy Committee initiated the establishment 
of two projects, one dealing with studies of form- 
ability and the other with fundamental informa- 
tion on deformation characteristics. Subsequently, 
these projects were endorsed by the Bureau of Aero- 
nautics, Navy Department, and their control num- 
bers were assigned. 

Project NRC-44 (NA-146), Formability of Mag- 
nesium Alloy Sheet, was established at the Univer- 
sity of California in December 1942 with the ob- 
jective of establishing design limitations and im- 
proving press and deep-drawing techniques. The 
program included the determination of variable 
speed stress-strain characteristics of magnesium al- 
loys, minimum bend radii in rubber-press forming, 
and the limits of the deep drawing of cups. This 
program was later extended to include studies of 
the forming of stretch flanges, beads on flat panels, 
shrink flanges by hydropress forming, and stretch 
forming of contour panels. 

Elevated Temperature Variable 
Speed Tensile Tests^® 

The most important fundamental data for the 
evaluation of the formability of metals is obtained 
from stress-strain curves. The formability of mag- 
nesium alloy sheet is limited at atmospheric tem- 
peratures, but it is sufficiently improved at elevated 
temperatures up to 700 F to make severe forming 


CONFIDENTIAL 


24 


AIRCRAFT MATERIALS 


feasible. At the elevated temperatures, however, 
the strain rate influences the plastic flow curve. 
Therefore, in order to provide adequate data for 
the determination of the formability of magnesium 
alloy sheet, flow curves were obtained for strain 
rates of about 10 inches per minute up to approxi- 
mately 140 inches per minute over the useful range 
of forming temperatures from 70 to 700 F. These 
data are directly useful in determining the sizes and 
dimensions of parts attainable in a number of the 
common forming operations. 

Grid analyses of the specimens yielded data for 
evaluation of the strains obtainable over various 
gage lengths for all conditions of strain rates and 
temperatures which were studied. These data pro- 
vide the numerical values that are essential in de- 
termining minimum bend radii and in determining 
values for stretching operations in general. 

Forming of Bends on the Guerin Press^^ 

The minimum bend radius for forming straight 
flanges of magnesium alloys at atmospheric temper- 
atures is too great for aircraft forming require- 
ments. Elevated temperature forming not only 
provides the possibility of producing adequately 
low minimum bend radii but also reduces the 
springback. The investigation on bending provided 
the essential design data for forming straight 
flanges over temperatures from 70 to 450 F for six 
standard magnesium alloy sheet materials. 

Evaluation of Deep-Drawing Properties at 
Elevated Temperatures^® 

The deep-drawing properties of annealed 1^2% 
Mn alloy, 3% Al, 1% Zn alloy, and 61 / 2 % Al, 

Zn alloy at elevated temperatures were determined 
by deep drawing cylindrical cups. The drawability 
was evaluated in terms of the maximum diameter 
and the maximum cup height which could be 
drawn successfully. Effects of punch radius, die 
radius, clearance, hold-down load, punch tempera- 
ture, and die temperature on the drawability were 
investigated. 

At room temperature only shallow draws are 
possible. At 500 F improved drawability is obtain- 
able, and at higher temperatures very deep draws 
can be produced. The highest drawability at eleva- 
ted temperatures was obtained with a heated die 
plate and hold-down pad and a water-cooled punch. 


On the basis of hot shortness and excessive grain 
growth, the maximum permissible drawing temper- 
atures of about 700 F for the l|/2% Mn alloy, 850 
F for the 3% Al, 1% Zn alloy, and 800 F for the 
61/2% Al, ^ 4 % Zn alloy were tentatively estab- 
lished. At these temperatures the maximum per- 
centage of draws obtained by using a water-cooled 
punch were approximately 67i%% for the li/2% 
Mn alloy, 671%% for the 3% Al, 1% Zn alloy, and 
65% for the 6i%% Al, ^% Zn alloy. 

Forming Shrink Flanges in the Guerin Press^^-^- 

Many aircraft parts consist of a flat web with a 
convex flange, generally produced on the Guerin 
press. The forming action consists of bending the 
flange around the die bend radius and simultane- 
ously shrinking the outer fiber of the flange from 
the original length in the blank to its length when 
the flange contacts the die. The maximum success- 
ful shrink obtainable depends on several factors. 

1. For a 360-degree flange, the flange height must 
be sufficiently small to prevent buckling of the flange. 

2. The die bend radius must be sufficiently large 
to prevent bend cracking. 

3. The pressure must be sufficiently great to per- 
mit complete forming. 

The improvement in shrink flange formability of 
magnesium alloys, in which buckling gives the 
forming limit for segment lengths 8 inches or 
greater, is minor at forming temperatures up to 
450 F. The investigation demonstrated that con- 
siderable improvement can be achieved, however, 
for room temperature and elevated temperature 
forming, if cutouts are used and if the resulting 
segment lengths are made about 2 inches in length 
or shorter. The increase in percentage of shrink for 
decrease in segment lengths is greater at elevated 
temperature forming than at room temperature 
forming. The shrink flange formabdity at 450 F 
for the 0.040-in. sheet is best for the annealed 
li%% Mn alloy and the poorest for the annealed 
61/2% Al, Zn alloy. The hard-rolled 61%% Al, 
Y 4 % Zn alloy, the hard-rolled 1%% Mn alloy, the 
annealed 3% Al, 1% Zn alloy, and the hard-rolled 
3% Al, 1% Zn alloy give intermediate results. The 
percentage of shrink which may be achieved for all 
segment lengths decreases with an increase in the 
die contour radius. 

Springback of the flange in shrink flange forming 
proved to be approximately the same as that for 


CONFIDENTIAL 


MAGNESIUM ALLOYS 


25 


Straight bends for the forming temperatures and ra- 
tios of die bend radius to sheet thickness investigated. 

Forming Beads in the Guerin Press^^ 

The major factor which determines the maxi- 
mum forming limit of beads is the maximum 
strain which may be achieved over the bead con- 
tour. Under all conditions which were investigated, 
it was found that the atmospheric internal beads 
fracture at or near the point of tangency of the cir- 
cular portion of the bead contour and the die bend 
radius. At the point of tangency local deformation 
was observed consistently for all test conditions 
Grid analyses revealed that the strains are essen- 
tially uniform over the entire circular portion of 
the bead contour. Maximum design limits were 
calculated from the grid analyses. 

The maximum uniform strains which can be 
achieved were found to increase with an increase 
in the forming temperatures up to 300 F. A de- 
crease in the maximum permissible strain was ob- 
served at 450 F as compared with that at 300 F for 
all alloys except the annealed li/ 2 % Mn alloy and 
hard-rolled 3% Al, 1% Zn alloy. Also, greater uni- 
form strain can be achieved with beads formed on 
external beading dies than those formed on in- 
ternal dies at the forming temperature of 70 F. The 
formability of magnesium alloy beads on external 
dies proved to be so good for most alloys at 70 F 
that no tests were run at elevated temperatures. 

Stretch Forming^^ 

The maximum permissible limits for the stretch 
formability of six magnesium alloys were deter- 
mined for a series of singly and doubly convex 
parts and also for a series of saddleback parts. The 
maximum permissible stretch at 70 F was small. 
At this temperature, stretch forming was found to 
be limited to contours where the maximum contour 
line is only a few per cent greater than the mini- 
mum contour line. The maximum permissible 
stretches were found to increase with increasing 
temperature over the range of temperatures in- 
vestigated. At 300 to 400 F, high stretches were 
successfully obtained and severely contoured doubly 
convex and saddleback parts were easily fabricated. 
Elevated temperatures also minimize the occurrence 
of grip failures and the presence of buckles in sad- 
dleback parts. 

The average stretches which were obtained ex- 


ceeded the uniform strain obtained in tension tests 
by wide margins. These data reveal that, contrary 
to prevalent opinion, the limits of stretch forma- 
bility are not dependent upon the uniform strain 
as obtained in a tension specimen, but frequently 
exceed this value. In several examples, strains ap- 
proximating the local ductility for the existing 
stress ratios were obtained over several inches of the 
maximum contour lines. The effect of die contour 
and friction are very important in influencing the 
maximum permissible stretches. Under ideal condi- 
tions of control of friction by means of lubrication 
and grip adjustment, it may be possible to approxi- 
mate the local ductility along the total length of 
the maximum contour line of the die. 

This project was carried out as an engineering 
investigation and provided much information on 
the requirements as to die design, press capacity, 
technique of carrying out operations at the proper 
temperature, considering the practical limitations, 
and on the way in which the different commercial 
alloys behave in response to many important vari- 
ables. While some cut-and-try methods will still be 
necessary in working out forming conditions for 
specific parts, a study of these reports should vastly 
decrease that necessity. They tell a good deal about 
how to form a part, but information on how that 
part may be expected to stand up in aircraft service 
was still scanty. Again, since extended actual air- 
craft use was lacking, reliance had to be placed on 
laboratory data. 

Two advisory reports bearing on the forming 
problems were submitted by the War Metallurgy 
Committee at the request of the University of Cali- 
fornia where they had been prepared as theses for 
advanced degrees. 

The first. Effect of Combined Stress on the Duc- 
tility of Metals,^^ reviews the existing knowledge 
on the subject and presents a method of calculat- 
ing permanent strains at fracture under combined 
stresses when (1) the stress combination at the be- 
ginning and end of plastic deformation and (2) the 
work hardening effects, are known. The calcula- 
tions based on the theory presented are in good 
agreement with the experimental data. 

The other report, Stress-Strain Relationships for 
Ji Magnesium Alloy Extrusion under Biaxial 
Stress, presents a study of some of the fundamen- 
tal assumptions of the theory of plastic flow under 
combined stresses. Few data are available on the 


CONFIDENTIAL 


26 


AIRCRAFT MATERIALS 


flow of metal under arbitrary conditions of stressing 
or straining, but this investigation indicates that 
good predictions of the strain are possible from a 
knowledge of the true stress-strain curve in tension 
and the known stress path. 

1.3.6 Deformation Characteristics 

By analogy to the other hexagonal metals, nota- 
bly zinc, it was indicated that the difficulties en- 
countered in the failures of magnesium alloy sheet 
might be due to the unusual deformation charac- 
teristics of this type of metallic structure. To obtain 
fundamental information on the relation between 
the internal structure of magnesium alloys and 
their ability to take deformation. Project NRC-70 
(NA-148), Deformation Characteristics of Magne- 
sium Alloys, was established at Carnegie Institute 
of Technology in June 1943. 

By means of X-ray and microscopic methods, the 
crystallographic and metallographic structure of 
magnesium was correlated with its deformation 
characteristics. This necessitated the development 
of a special etching technique which would at once 
reveal both the grain structure and the twinning 
due to mechanical working.^^ 

The program of the investigation embraces two 
problems: (1) investigation of the mechanics of de- 
formation in sheets, covering slip, twinning, crack 
propagation, microstructure, and preferred orienta- 
tion, and their relation to physical properties; (2) 
investigation of possible presence of embrittling 
agents, perhaps oxide films in the metal, or possibly 
nitrogen, carbon, sulphur, chlorine, or other im- 
purities, and exploration of the possibility of pro- 
ducing more ductile material by the elimination 
of them. 

The work indicated that avoidance of directional 
properties in sheet that result from the tendency 
of magnesium to form twin crystals can be achieved 
by the right combinations of hot and cold work. 
It was demonstrated that twinning depends on the 
speed and temperature of deformation, decreasing 
with increasing temperature and decreasing speed 
of deformation. The pronounced change in orienta- 
tion (86 degrees) which is produced by twinning, 
combined with the above knowledge, was employed 
to produce randomly oriented magnesium sheet. 
The tensile strength of this sheet was slightly lower 
and the reduction of area slightly higher than that 


of commercial sheet. Such randomly oriented sheet 
may be desirable for certain operations where 
isotropy is of prime importance. However, the ex- 
treme ease with which the twinning takes place at 
room temperature, returning the sheet to its nor- 
mal orientation, makes extremely doubtful the pro- 
duction of magnesium sheet with any marked im- 
provement in room temperature properties by 
alteration of orientation of its crystals. Further- 
more, the production of randomly oriented sheet 
may complicate rolling practice. Twinning occurs 
less readily at elevated than at room temperature, 
but, under rapid deformation in forging or rolling, 
it may occur even at elevated temperature. 

Different lots of magnesium and the same lot 
cooled at different rates after freezing fracture in 
different ways, that is, either intercrystalline or 
transcrystalline. Intercrystalline fracture is thought 
to denote less dependable material. Metallographic 
studies revealed the presence of an impurity in 
magnesium melted from distilled crystals. It was 
suspected that this impurity was thrown out of 
solution during cooling, and that when the precipi- 
tation occurred at grain boundaries, it was the 
cause of intercrystalline fractures. Sublimation 
studies at 480 C in a vacuum of 0.005 micron in- 
dicated the presence of thin films, believed to be 
MgO, located at the grain boundaries and extend- 
ing in from the thicker film of MgO that forms the 
outer surface of the sample. The problem of pro- 
ducing metal or purifying it so it is free from such 
impurities thus appears to be of basic importance. 
Certain degrees of deformation prior to heat treat- 
ment accentuate the propensity for the impurities 
to separate at the grain boundaries where they are 
harmful. 

Although incompleted, this project was not ex- 
tended because at that time, November 15, 1944, 
it was felt that it could not be completed in time 
to be of value in World War II. Five progress re- 
ports^^’^®’^^’®^’®^ give the details of the experimen- 
tal work, and a final report®^ summarizes the results 
of the investigation. 

Status of Research on Magnesium 
Alloys 

In addition to the work done by NDRC, con- 
siderable research was carried out on magnesium 
alloys during World War II by the magnesium pro- 


CONFIDENTIAL 


MISCELLANEOUS MATERIALS 


27 


ducers, the aircraft industry, the Armed Forces, 
NACA, and OPRD. The NACA Committee on 
Materials Research Coordination compiled a listing 
of these research projects and, in order to deter- 
mine the research needs that required attention, 
requested the War Metallurgy Committee to re- 
view the projects completed and being carried out 
and to make comments and suggestions as to re- 
search that should be undertaken. 

In February 1945, the War Metallurgy Commit- 
tee established Survey Project SP-26, A Survey of 
Research on Magnesium Alloy Being Conducted by 
Government Agencies, Branches of the Armed Ser- 
vices, and Producers and Fabricators of Magnesium. 
The report on this project®^ comprises three major 
sections: (1) a summary of the current and cur- 
rently interesting research projects on magnesium, 
(2) suggestions and comments on this research and 
on magnesium, obtained from those interested in 
the use of the metal, and (3) a recapitulation of the 
first two sections, with suggestions as to which re- 
search and development work appears to be most 
necessary to make magnesium a more useful metal. 

A digest of the report led to the following general- 
izations of the research needs in magnesium alloys: 

1. The greatest need appears to be for improved 
magnesium alloys for wrought products, especially 
sheet. The features most desired for aircraft appli- 
cations are: less sensitivity to stress-corrosion crack- 
ing; higher mechanical properties, particularly ten- 
sile and compressive yield strengths; lower notch 
sensitivity; decreased flammability; greater ductility 
and the ability to be cold-worked. 

2. An observed impurity in “pure” magnesium 
should be studied for its influence on the present al- 
loys and on any new alloys which may be developed, 
with the idea that this impurity may be potent in 
determining the properties of these alloys. Methods 
of removing or controlling this impurity during the 
melting of the alloys should be investigated. 

3. There is a need for the engineering develop- 
ment of experimental units employing magnesium 
to be used in evaluating the serviceability of mag- 
nesium structural parts and to serve as a source of 
engineering information for those interested in ap- 
plying the metal. 

4. The development of improved melting meth- 
ods and molding techniques presents the best ap- 
proach to the eventual production of higher quality, 
lower cost, sand, permanent mold, and die castings. 


To make available the information collected in 
this survey to universities and to other research 
agencies contemplating research on magnesium al- 
loys, in September 1945 the NACA Committee on 
Materials Research Coordination requested the 
War Metallurgy Committee to appoint a special 
committee to review the above-described report and 
to point out where additional research might be 
warranted or where the scope of the existing proj- 
ect might be expanded to advantage. An unclassi- 
fied supplementary report®*^ was issued covering 
the specific topics upon which research is recom- 
mended. The NACA Committee on Materials Re- 
search Coordination proposes to reduplicate this 
report for wide circulation in order to promote 
research on magnesium in the fields of greatest im- 
portance at this time. 

1.3.8 Indexing of Division 18 Reports 
on Magnesium Alloys 

An index®’^ of the Division 18 reports on the mag- 
nesium alloys was prepared by the Research Infor- 
mation Division of the War Metallurgy Committee. 
This index covers the subject list of the various proj- 
ects with the reports issued on each, a brief abstract 
of each report, and a subject index of the reports. 
Also included is a table of the commercial mag- 
nesium alloy symbols and compositions. This index 
should add to the usefulness of the many reports on 
the subjects. 

14 MISCELLANEOUS MATERIALS 

Control Cables 

In December 1941, the Coordinator of Research 
and Development, Navy Department, suggested 
that NDRC initiate investigations to develop air- 
craft control cables with improved wear resistance. 
The cable which was being furnished to the Bureau 
of Aeronautics in accordance with Navy Specifica- 
tions ANRRC-43 and ANRRC-48 was fabricated 
from 18-8 stainless steel or tin-coated carbon steel. 
A number of failures had been reported after 100 to 
150 hours in service, while in other cases the service 
life was from 800 to 1,000 hours. The Navy Depart- 
ment was interested in determining the causes of 
these failures as well as in developing satisfactory 


CONFIDENTIAL 


28 


AIRCRAFT MATERIALS 


cables from noncritical materials. A brief program 
of investigation was to be conducted at the Naval 
Aircraft Factory to obtain some information on the 
problem. Owing to time limitations and lack of 
facilities at the Naval Aircraft Factory, the program 
could not cover the entire field. Consequently, the 
Office of the Coordinator of Research and Develop- 
ment requested that NDRC undertake a compre- 
hensive investigation. After meetings between 
representatives of the War Metallurgy Committee, 
the Bureau of Aeronautics, and John A. Roebling’s 
Sons Company, the largest producers of aircraft 
control cable for the Navy, Project NRC-15 (N-101), 
Corrosion-Fatigue Failure of Aircraft Control 
Cables, was established in May 1942 in the research 
laboratories of John A. Roebling’s Sons Company. 

The original program embodied the determina- 
tion of the effects of composition and operating 
conditions on the performance of control cables as 
shown by standard wire cable fatigue tests, corro- 
sion fatigue tests, and low-temperature fatigue tests. 
Since this original program was designed for the 
development of improved cables using 18-8 stainless 
steel wire and since the supply of alloying elements 
for stainless steel was becoming more critical, the 
program was modified to include the investigation 
of galvanized carbon steel cables, as well as cable 
lubricants for low-temperature service. The pro- 
gram was subsequently extended to include the 
determination of cable performance with actual 
service loads and sheaves for the purpose of obtain- 
ing data which could be used in the design of air- 
craft control systems. 

Among the various factors affecting the fatigue 
failure of control cables are the tension on the cables 
as installed, the ratio of sheave diameter to cable 
diameter, the material of the sheave, the number of 
wires in the cable and their arrangement within it, 
the material of the wires and their surface (plain or 
coated), the corrosive conditions to be met and the 
protection against corrosion, the temperatures in- 
volved, and the lubricants within the cable. 

The cable sizes investigated were i/g in., %2 > 

%(. in., in., and in. in diameter with a 7 by 
19 construction, and %2 ^v4th a 7 by 7 construc- 
tion. The materials included 18-8 stainless steel and 
carbon steel, bright, galvanized, tinned, and lead- 
alloy coated. The galvanized cables were made of 
wire with various weights of hot galvanized and 
electrogalvanized coatings. Standard commercial 


lubricants and special lubricants containing lithium 
soap grease, mineral oils, paralketone neutral base, 
rust preventative, and extreme pressure additives 
were studied. 

The fatigue and internal friction properties of 
cable as affected by corrosion in a salt atmosphere 
and by temperatures ranging from -|-160 F to —65 
F were studied. The fatigue properties of cables 
were investigated under normal laboratory condi- 
tions with sheaves and loads similar to those used 
in aircraft control systems. The results of these 
tests with 1 per cent loads showed that under the 
severe conditions of a salt atmosphere and at —65 
F, 18-8 stainless steel cables were the most effective. 
However, without corrosion and at room tempera- 
ture, carbon steel cables are equal to or better than 
stainless steel cables. Service load fatigue tests 
in the absence of corrosion showed that 18-8 stain- 
less steel has a considerably lower fatigue life than 
galvanized carbon steel cables. Heavy galvanized 
cables are the best of the carbon steel cables for 
corrosion fatigue but have the poorest fatigue life 
at —65 F. The tin-lead alloy and light zinc coatings 
did not materially improve the corrosion fatigue 
life of bright carbon steel cables. The tinned cables 
had the lowest internal friction in the absence of 
corrosion. Corrosion by salt spray increases the in- 
ternal friction of tinned cables and decreases that 
of heavy galvanized cables. The continuous flexing 
of the cables during fatigue test in the absence of 
corrosion lowers the internal friction of the galvan- 
ized cables but not sufficiently to equal that of the 
tinned cables. The internal friction of cables in- 
creases with an increase in cable tension and a de- 
crease in sheave diameter. 

The fatigue and internal friction of cables are 
improved by the use of lubricants. The effectiveness 
of lubricants is dependent upon the temperature and 
the protection which they afford against corrosion. 
The commercial cable lubricants are affected consid- 
erably by temperature, whereas some of the greases 
perform quite uniformly over the range of tempera- 
tures investigated. Externally applied paralketone 
(An-C-52) is very effective in providing protection 
against corrosion, but it becomes brittle at —65 F 
and flakes off the cable where it bends over a sheave. 

The service load tests with micarta and 24S-1 
aluminum alloy sheaves indicated that for a given 
cable tension the fatigue life was satisfactory pro- 
vided the ratio between the sheave diameter and 


CONFIDENTIAL 


MISCELLANEOUS MATERIALS 


29 


cable diameter was above a critical value. The criti- 
cal sheave ratio increases with the cable tension. For 
a 1 per cent load, the critical sheave ratio for 7 by 

19 galvanized cables is approximately 10; for 10 and 

20 per cent loads, the ratio is approximately 20 and 
28, respectively. The relationship between the visible 
wire breaks and the average loss in strength was inves- 
tigated, as well as that between the loss in strength 
and the number of reversals in fatigue under various 
load conditions for 7 by 19 galvanized cables. The 
fatigue life of 7 by 7 construction cables with 1 per 
cent loads is less than that of 7 by 19 construction 
cables with the same loads and sheave ratios. 

The AN-210 micarta pulleys operate satisfactorily 
under relatively low service loads, but under higher 
loads they fail by wear, splitting, or bearing failures. 
The 24S-T aluminum alloy sheaves equipped with 
large ball bearings operate satisfactorily under loads 
up to 60 per cent of the specified cable strength. 

The results of the investigation are summarized 
in the final report®® on the project, while the prog- 
ress reports present the many details of the inves- 
tigation, covering integral phases of the investiga- 
tion as follows: the effect of lubrication on fatigue 
properties,®^ the effect of metallic coatings and lubri- 
cants on fatigue properties,®® the effect of sheave 
diameter on fatigue life,®® the effect of metallic coat- 
ings and lubricants on fatigue and internal fric- 
tion,"^® fatigue tests under service loads,"^! and mis- 
cellaneous tests and the examination of German 
and Japanese aircraft cables."^- 

From the experiments made and data presented, 
the mechanical details and the proper type of lubri- 
cation for satisfactory service are made clear. The 
choice of cable material will vary according to serv- 
ice conditions. This comprehensive work has mate- 
rially clarified the problems of design of control 
cable installations and the methods of testing the 
cable to insure reliability and long life. 

Surface Prestressing of Metallic 
Materials 

During World War II, considerable progress was 
made toward the application of fundamental knowl- 
edge to problems of practical significance. A char- 
acteristic example of this type is the wide 
application of surface peening, the basic theory of 
which had been developed between 1920 and 1930 
with little support from industry. 


It has been known that cold working the surface 
of a part greatly increases its endurance under con- 
ditions of repeated stress, which are of such nature 
that failure tends to start at the surface. In analo- 
gous fashion, carburizing or nitriding the surface 
increases its endurance as long as cracks do not start 
in the hard surfaces. However, it is known also that 
the cold-worked surface can be over-cold worked 
to such an extent that cracks are formed, in which 
case the cold work can do more harm than good. 

The advent of high-frequency surface hardening 
and of flame hardening brought the realization that 
surfaces can be hardened and strengthened by these 
means much more rapidly than by carburizing and 
nitriding. 

Surface peening by impact of hard balls^ the 
“cloudburst hardening” method, had been used 
more as a method of evaluating uniformity of hard- 
ness than as a processing method for improvement, 
though the latter aspect was given some attention. 

Springs normally are very highly stressed, and 
their fatigue behavior is governed by the condition 
of their surface. Automotive valve springs were es- 
pecially prone to failure. In 1926, an epidemic of 
valve spring failures in one motorcar was overcome 
by shot peening. Shot peening of springs used for 
individual wheel suspension on automobiles soon 
followed with gratifying results. Surface peening 
had proved to be effective in increasing the fatigue 
life of some machine parts at their operating loads 
by 200 to 1,500 per cent. 

These commercial examples brought to the atten- 
tion of the automotive industry the value of cold 
working the surface of parts subject to fatigue. In 
that industry, some individuals became enthusiastic 
about the possibilities of shot peening and, through 
many articles in technical journals, a missionary 
campaign had been carried on for its more wide- 
spread application. 

In order to determine the possibilities and limi- 
tations of surface peening for the improvement in 
service life of engine and structural parts of air- 
planes, the Bureau of Aeronautics, Navy Depart- 
ment, requested NDRC to initiate investigations 
on the subject. Two projects were established, one 
on shot peening and one on induction hardening. 

Shot Peening 

Project NRC-40 (NA-115), Effects of Shot Blast- 
ing on Mechanical Properties of Steel, was carried 


CONFIDENTIAL 


30 


AIRCRAFT MATERIALS 


out by the Research Laboratories Division of Gen- 
eral Motors Corporation. The objective of this proj- 
ect was twofold: (1) to correlate and develop 
principles for the practical application of mechan- 
ical surface treatments by a study of their effects 
on the properties of different materials in various 
sizes, and (2) to develop techniques for the mechan- 
ical surface treatments of certain specific engineer- 
ing parts such as engine connecting rods, propeller 
blades, fusion steel weldments, landing gear cast- 
ings, etc. 

For the most part, the investigation comprised 
(1) the experimental shot peening of numerous 
parts of military equipment and a substantial num- 
ber of laboratory specimens which then were tested, 
largely in other laboratories, and (2) the assembly 
and consolidation of pertinent data into case his- 
tories. The effect of shot peening was determined 
on fatigue durability, static strength, impact, dimen- 
sions, hardness, friction, stress-corrosion cracking, 
corrosion, surface roughness, and surface failure. 
Studies also were made of the shot-peening process 
and equipment and methods of measuring the in- 
tensity of peening. 

The principal generalizations on the effects of 
shot peening on the properties of various parts '^3,74, 
75,76 are as follows: (1) fatigue properties are 
improved, (2) there is little influence on static 
strength, (3) the effect on resistance to impact is 
not determined fully, (4) the effect on hardness is 
not established fully, although there is an indica- 
tion that hardness may be increased slightly, (5) 
frictional properties of sliding surfaces are some- 
what affected, (6) the tendency toward stress-corro- 
sion cracking of brass and magnesium alloys is 
reduced, (7) general corrosion is not reduced, (8) the 
roughness of the surface of shot-peened steel varies 
in depth up to 0.0040 in. depending upon the shot 
size and peening intensity used, and (9) its influence 
on surface failures such as pitting, galling, scuffing, 
scoring, and fretting corrosion is not yet established. 

A major difficulty in the application of shot peen- 
ing has been knowing when to stop, that is, ascer- 
taining to what degree peening should be carried 
to secure optimum results and yet to preclude over- 
cold working and the starting of cracks. This is 
still a difficulty, and the performance, in actual or 
simulated service, of parts peened to different de- 
grees is the final criterion. Once this is known, 
directly or by analogy, the degree of peening can 


be regulated to produce the optimum by subjecting 
one side of a standard test strip of a standard steel 
to the intensity and time of peening it is desired to 
use on the part in question and by noting the 
amount of bowing that is produced. 

The conditions of greatest applicability of sur- 
face cold working occur where a part is failing after 
relatively few applications of repeated stress, the 
stress being at a very high level, considerably above 
the endurance limit of the material. Such high 
stresses may have to be applied because of an initial 
design error, and because space limitations permit 
no opportunity to redesign to bring the stress down 
to a proper level. However, a limited life may be 
accepted for the sake of saving weight. Because of 
this, the comparisons of peened versus nonpeened 
parts are often made at a single level of repeated 
stress in terms of life at that stress rather than over 
a range of stresses such that endurance limits would 
be determined. In terms of life, a stress often can 
be chosen just above the knee of the fatigue curve 
such that the increased life appears most phenom- 
enal and spectacular, but around the knee of the 
curve, duplicate determinations often show very 
wide scatter and more than a few tests are needed 
to establish the true life expectancy. While a selec- 
ted test stress may, therefore, give an exaggerated 
picture of the real improvement, there is plenty of 
evidence that in the cases where surface hardness is 
helpful, the improvement is decidedly worth while. 

After the project had been in progress about a 
year, it became evident that the practical achieve- 
ments were contributing more to the war effort 
than the more fundamental research work. There- 
fore, emphasis was shifted to “trouble shooting,” 
namely, (1) giving service to war production plants in 
overcoming failure of machine parts by surface treat- 
ment, thus avoiding changes in design or tool equip- 
ment, (2) increasing the fatigue strength of machine 
parts, thus permitting increase in power input, and 
(3) reducing the labor in finishing machine parts 
by eliminating polishing and manual operations. 

A few applications were not helpful or were of 
doubtful value. Magnesium alloys subject to stress- 
corrosion were shot peened, but particles of iron 
from the shot greatly accelerate general corrosion and 
are difficult to remove. The remedy was to use glass 
beads instead of iron shot. Shot peening of light 
armor plate did not improve its ballistic behavior. 
On some parts of a severely notched contour, tested 


CONFIDENTIAL 


MISCELLANEOUS MATERIALS 


31 


in impact, the hardening of the surface was no help. 
On others, more smoothly contoured, it was useful, 
one peculiar case being a carburized pitman arm ball 
on which the impact was not improved at room 
temperature but was greatly improved at —60 F. 

A malleabilized iron, engine valve rocker arm, 
which failed on engine tests in 18 to 58 hours when 
nonpeened, consistently survived 140-hour tests 
when shot peened. 

A spectacular result was obtained in a laboratory 
tension-compression fatigue test on Allison engine 
connecting rod bolts where, by cold rolling the 
threads and shot peening the balance of the bolt, 
the life under the particular test conditions was in- 
creased 16 times. 

Oerlikon gun hammers of regular production 
failed in 8,000 to 30,000 rounds, while those shot 
peened lasted 20,000 to 40,000 rounds. The aver- 
age life of several parts for a 20-mm AN-M2 
gun were doubled or more by shot peening. In 
general, the shortest life for the peened part was 
somewhat greater than the longest life of an un- 
peened one, but the scatter was wide in both cases. 

A recoil spring heat treated to 61-63 Rockwell C 
failed in about 5,000 cycles. When shot peened, it 
withstood 400,000 to 700,000 cycles. 

Articulated Pratt 8c Whitney connecting rods, 
laboratory tested, were compared (1) with rods 
which had the usual highly polished finish and (2) 
with rods which were rough polished, then shot 
peened. At a calculated maximum stress of 90,000 
psi, the former ran 80,000 to 100,000 cycles, the lat- 
ter, 90,000 to 240,000. At 80,000 psi, the former ran 
200,000 to 400,000 cycles, the latter, 400,000 to 
1,000,000. During the shot peening, the diameter of 
the 1-in. and li/^-in. holes in the connecting rods in- 
creased by about 1/10,000 to 4/10,000 in. and the 9-in. 
overall length increased by some 20/10,000, evidence 
that compressive stress was induced at the surface. 

It is argued that this compressive stress provides 
increased resistance to fatigue failure, since it is 
tensile stress (tending to open and extend a crack 
once formed) that produces the damage, whereas, 
if compressive stress is present, that stress must be 
released by the applied tensile stress, thereby de- 
creasing the effective tensile stress. It is argued also 
that it is this compressive stress rather than the 
strengthening of the surface that confers improved 
fatigue resistance. The results from some of the case 
histories demonstrate rather spectacular improve- 


ment. In other cases it is a tossup whether any im- 
provement has been effected. In a few cases actual 
deterioration occurs, as in a case of a final drive 
pinion carburized and treated to 58-65 Rockwell C. 
On the other hand, a carburized ring gear at the 
same hardness was much improved. On torsion bars, 
surface rolling was equivalent to shot peening. 

An enthusiastic “missionary” attitude prevailed 
throughout the reports, and on the whole this was 
justified. Specific exceptions bring out the impor- 
tance of avoiding over-cold work, the existence of 
scatter, and the necessity of putting the peening 
operation under close control. 

A factor to consider is decarburization, which is 
extremely damaging in fatigue, this damage not 
being entirely repairable by peening. In evaluating 
the benefits of peening, concurrent attention must 
be paid to decarburization. 

One of the useful conclusions to be drawn from 
the assembled case histories is that some improve- 
ment ordinarily is to be expected from the treat- 
ment, but there are sufficient exceptions to prevent 
its being classified as a cure-all. Especially where the 
life of unpeened parts shows a wide variation, the 
causes of that scatter are not necessarily overcome 
by peening, so that there also may be correspond- 
ingly wide scatter in the life of the peened parts. 
Experience with large numbers of tests and evalua- 
tion of the data from the probability point of view 
would be required to appraise such cases accurately. 

In July 1944, the Office of the Chief of Ordnance, 
Army Service Forces, requested NDRC to under- 
take the preparation of a manual on the shot peen- 
ing process and its effective application for the 
guidance of design engineers. This project, OD-177, 
was not undertaken since there was insufficient time 
or personnel to carry out the more important 
phases of the original program and prepare the 
manual as well. The Research Laboratories Divi- 
sion of General Motors Corporation recognizes the 
need for such a manual, however, and plans to pre- 
pare one when time permits. 

Induction Hardening 

To augment the studies of surface pre-stressing by 
shot peening. Project NRC-78, Study of Surface Pre- 
Stressing on Dynamic Properties of Metals, was estab- 
lished in the research laboratories of the General 
Electric Company. The aim of the program was to 
study the effects of flame and induction hardening. 


CONFIDENTIAL 


32 


AIRCRAFT MATERIALS 


carburizing, nitriding, cyaniding, etc., on the fatigue 
life of various metal parts of war materiel. Since the 
progress was not encouraging on the initial phase of 
the program, which consisted of experimental induc- 
tion heat treatments on SAE 1050, XI 050, and a 
chromium-molybdenum steel, the project was aban- 
doned. It was indicated, however, that the fatigue en- 
durance limit is increased by 50 per cent and that the 
origin of fatigue failures in induction-hardened bars 
is sub-surface. It was found also that induction hard- 
ening produces tension in the center of cylinders and 
compression at the surface. The report on this work 
was not issued because more comprehensive informa- 
tion of this nature can be found in the technical 
literature on induction hardening. 


Rubber Branch. 

Part IX Fuel and Lubricant Test Methods of 
the Chemical Branch. 

Part X Paint and Protective Coating Test 
Methods of the Chemical Branch. 

Part XI Rubber Test Methods of the Textile 
and Rubber Branch. 

Part XII Title Index of Parts I to XI, Inclusive. 

These reports are unclassified and were distribu- 
ted widely throughout the aircraft industry as well 
as to the Armed Services. In addition, the Materials 
Laboratory of Wright Field has reduplicated these 
reports for distribution to suppliers of aircraft mate- 
rials so that they may utilize in their own testing 
the methods by which their materials will be evalu- 
ated by the Army Air Forces. 


1 . 4.3 


Methods of Testing Aircraft 
Materials 


The test methods used by industry for evaluating 
the various materials used in aircraft construction 
frequently vary considerably from those used by the 
testing and procurement agencies of the Army Air 
Forces and the Bureau of Aeronautics, Navy Depart- 
ment. In order to promote the standardization of 
these test methods, the NACA Committee on Mate- 
rials Research Coordination requested the War 
Metallurgy Committee to review and compile the 
test methods currently in use at the Materials Labo- 
ratory, Engineering Division, ATSC, Wright Field. 

Accordingly, Survey Project SP-24 was established 
and carried out. Twelve NDRC reports were issued 
covering the test methods used at Wright Field on 
various aircraft materials, as follows: 

Part I Test Methods of the Structural and 
Mechanical Test Branch. 

Part II Test Methods of the Metallurgical 
Branch. 

Part III Routine Chemical Analysis Methods 
of the Physics Branch. 

Part IV Test Methods of the Wood and Glue 
Branch. 

Part V Electrochemical Methods of the Chem- 
ical Branch. 

Part VI Physical Test Methods of the Physics 
Branch. 

Part VII Test Methods of the Welding Branch. 

Part VIII Textile, Paper, Leather, and Fungi- 
cide Test Methods of the Textile and 


1.4.4 Fatigue of Aircraft Structures 
and Materials 

Both laboratory tests and service experience have 
demonstrated that a structural material will fail 
after many repetitions of a stress which is substan- 
tially less than the stress at which failure occurs un- 
der continuously increasing load. Such failure under 
repeated loading is called failure by fatigue. Since 
aircraft structures particularly are subject to vibra- 
tion, impacts, and other repetitive loads, it is rea- 
sonable to anticipate the failure of some aircraft 
parts by fatigue. 

Present aircraft structural designs are based upon 
static load distributions and generally have afforded 
adequate fatigue strength in primary structures. 
Prior to 1939, few failures had occurred in which 
fatigue was a primary cause, and in no instance had 
it been proved that any airplane wing spar or air- 
ship structural girder had failed in service owing to 
fatigue. Fatigue failures, noted since then, have 
been very few in proportion to all known aircraft 
failures. 

Nevertheless, present trends in modern airplane 
design may lead to greater danger of fatigue failure 
in the near future. Higher speeds, increased wing 
loading, and in military planes increased fire power 
and maneuverability tend to produce greater dy- 
namic loading. The use of new materials which 
have higher static strengths, but which do not have 
proportionately higher fatigue strengths, increases 
the possibility of failure of parts by fatigue. Radical 


CONFIDENTIAL 


MISCELLANEOUS MATERIALS 


changes in design, as may occur in jet-propelled 
ships or in rotary-wing aircraft, need to be consid- 
ered in the light of dynamic loading and possible 
fatigue failure of parts. 

To determine the extent and nature of the avail- 
able information on the fatigue properties of ma- 
terials and structures in aircraft so that research 
needs could be ascertained, the NACA Committee on 
Materials Research Coordination requested the War 
Metallurgy Committee to review the published and 
unpublished information available from aircraft 
companies, manufacturers, and other laboratories. 

To carry out this survey, the War Metallurgy 
Committee established Survey Project SP-27, Fa- 
tigue Properties of Aircraft Materials and Struc- 
tures. Although there had been many instances of 
fatigue failures of attachments and fittings which 
are not structurally important, the study was lim- 
ited to the primary load-bearing structure of the 
airframe. Engines and propellers also were omitted 
because of the considerable amount of readily avail- 
able information concerning the fatigue properties 
of their materials and parts. 

More than 1,000 references were reviewed from 
the library of Battelle Memorial Institute, from air- 
craft manufacturers, and from other laboratories. 
Of these, about 600 concern the fatigue properties 
of materials. Fewer useful references were found 


concerning the fatigue properties of airframe struc- 
tural elements, repeated-load tests of assemblies, 
and service loading of aircraft structures. 

Part I of the report on this survey"^^ summarizes 
available information concerning the fatigue prop- 
erties of materials commonly used in airframe con- 
struction. This summary is designed to indicate the 
extent of available information rather than to offer 
a handbook of design values. For many details, re- 
ference is made to available publications. 

Part II summarizes the results of fatigue tests on 
fabricated parts, on simple joints, and on stiffened 
panels. Although actual stress values usually are not 
known, the tests are of considerable interest because 
they include the effects of the stress raisers and sur- 
face conditions encountered in production. 

Part III describes results of typical tests of struc- 
tural assemblies under repeated loads. Such tests in- 
clude an additional factor of importance in service, 
namely, the deflection characteristics of the struc- 
ture under the dynamic loading applied. 

Part IV of the report discusses the correlation of 
information from laboratory fatigue tests with in- 
formation from service records of loading during 
flight and landings. This discussion does not con- 
tain definite conclusions for use in design, but sum- 
marizes available information and points out prob- 
lems for future consideration. 


CONFIDENTIAL 


Chapter 2 

ARMOR 


21 INTRODUCTION 

E arly in 1942 the War Metallurgy Committee ini- 
tiated several research projects in the metallurgy 
of armor as a result of the recommendations of the 
NDRC ad hoc Committee on Armor Plate in its 
report to Dr. James B. Conant, dated November 
18, 1941. "IS These projects comprised studies on in- 
vestigations of the effects of hydrogen, oxygen, and 
nitrogen in armor plate, the correlation of the 
metallographic structure of armor plate hardness, 
and the development of a nonballistic test for de- 
termining armor plate quality. At the same time, a 
comprehensive investigation of fundamental prob- 
lems in production and heat treatment of armor 
brought about by the critical shortages of the alloy- 
ing elements used in armor plate at the beginning 
of World War II was initiated at the suggestion of 
Watertown Arsenal. Starting with problems of con- 
servation and substitution, this work included stud- 
ies of the influence of melting practices on the 
resultant armor, the effects of various elements on 
the quench-cracking susceptibility of cast armor, 
the effects of heat treatments on the properties of 
homogeneous armor plate, and the development of 
improved methods for the production of homogen- 
eous armor plate and of face-hardened armor plate. 
Supplementary projects were established for a more 
detailed investigation of other problems such as the 
use of boron as a hardening element, the use of 
flame hardening, and the development of low-alloy 
armor compositions. All this work was carried out 
in close cooperation with Watertown Arsenal and 
with the Subcommittees on Cast and Rolled Armor, 
Ferrous Metallurgical Advisory Board, Ordnance 
Department, the membership of which included 
many representatives of the various producers of 
cast and rolled armor, as well as government repre- 
sentatives. Reports on this work were distributed 
to the members of these subcommittees at the re- 
quest of the Ordnance Department. 

2 2 CORRELATION OF TESTING 
METHODS 

Determining the suitability and acceptability of 
armor by ballistic testing at the Proving Grounds 


is an expensive and time-consuming task. The test 
has been appraised by those in position to know it 
as “arbitrary and not sufficiently discriminating.” 
If more precise ballistic tests or some simpler 
method of evaluation could be found whose corre- 
lation with actual ballistic tests were definitely and 
fully established, the development of better armor, 
the proving of suitability of alternate, alloy-saving 
compositions, and the prompt acceptance or rejec- 
tion of armor would be facilitated. 

As a result of the recommendations of the NDRC 
ad hoc Committee on Armor Plate,^^ the War 
Metallurgy Committee established at Carnegie In- 
stitute of Technology Project NRC-6 (OD-84), Non- 
Ballistic Test for Armor Plate. The investigations 
made on this project established a rough correlation 
between poor ballistic behavior of rolled homogen- 
eous armor of li/^-in. and 2-in. thickness and either 
the reduction in area on specimens taken in the 
thickness direction or the low energy absorption of 
normal-size notched impact specimens broken at a 
low temperature. That is, with certain reservations, 
the conclusion was reached that good ballistic be- 
havior is characteristic of rolled homogeneous armor 
plate in which the reduction of area in the thick- 
ness-tensile test is consistently greater than 30 per 
cent and the V-notch Charpy values exceed 25 ft-lb 
at minus 40 C, whereas plates in which the reduc- 
tion of area in the thickness-direction tensile test 
falls below 10 per cent and the V-notch Charpy 
values at minus 40 C are less than 17 ft-lb will be 
rejected by ballistic tests. 

These conclusions are valid only when the failure 
to pass Specification AXS 488 is caused by cracking 
or because the exit dimension in the penetration- 
through-plate test is in excess of the specification 
limit. Furthermore, they are applicable only when 
the uniformity of a lot of armor plate has been 
established by an adequate number of both types 
of tests. These conclusions do not apply to badly 
laminated plate for which the properties are known 
to be widely different at different points, nor to lots 
of plate which for any other reason are markedly 
nonuniform. 

Some theoretical justification of these conclusions 
was claimed on the grounds that high impact 
velocity allows little deformation and in low-tem- 


34 


CONFIDENTIAL 


CORRELATION OF TESTING METHODS 


35 


perature tests deformation is likewise restrained.*® 
However, consideration immediately brings out a 
significant lack of similiarity in the two cases, for, 
when a projectile hits armor, the spot becomes ex- 
tremely hot, a condition which is lacking in 
notched-bar tests. 

In any event, the assumption of a basic correla- 
tion rests on inadequately demonstrated grounds, 
since cases are on record where armor which the 
impact test would reject passes ballistic tests and 
vice versa. Therefore, it must be concluded that a 
nonballistic test sufficiently discriminating to dif- 
ferentiate the acceptable from the unsatisfactory 
armor w’as not developed on this project. 

However, the indications are that a li/^-in. or 2- 
in. plate with less than 10 per cent reduction of 
area (averages of six specimens) in specimens taken 
normal to the plate will fail by back spalling, that 
is, the exit dimension in penetration will exceed 
the specified limit. Such plate could be rejected 
without ballistic test. Plate wdth values of 30 per 
cent or over will not fail by back spalling and, if 
there is adequate evidence that such a plate would 
have proper resistance to penetration, ballistic test- 
ing might be omitted, provided that the plate were 
also resistant to cracking. Cracking is not necessar- 
ily prevented by high ductility. Plates with 50 to 
60 per cent reduction of area on specimens taken 
normal to the plate have failed by cracking, while 
others with 15 per cent reduction of area have been 
acceptable. 

Cracking showed a fair correlation with notched 
impact behavior. Data from standard Charpy V- 
notch specimens, taken with the long axis in the 
width direction of the plate and the notch in the 
thickness direction and at —40 C indicated that 
plates with over 25 ft-lb Charpy value will be free 
from cracking, while those under 17 ft-lb usually 
are not. There was no correlation between notched 
bar results and spalling. 

It is recognized that the spread in energy ab- 
sorbed between plates that have been accepted and 
those that have been rejected is at times small in- 
deed. It is well known that the type of fracture, 
whether fibrous or brittle, is of quite as much im- 
portance in evaluating notched behavior as is the 
numerical figure of ft-lb of energy absorbed. One 
important advantage of the notched-bar test using 
either the small Charpy specimens or the fracture 
specimen recommended by Army Ordnance is that 


the type of fracture, whether fibrous or brittle, is 
readily disclosed. 

Various other lines of attack failed to show any 
correlation between the other mechanical proper- 
ties and cracking or spalling. Only the two prop- 
erties mentioned held forth any promise. 

It must be recognized that an insufficient number 
of plates were tested to allow evaluation of the data 
by probability methods or to justify drawing sweep- 
ing conclusions. Further extensive work is necessary 
to prove a degree of correlation that would justify 
substitution of tests of either reduction of area in 
the plate-thickness direction or Charpy notched-bar 
results for ballistic testing in specifications for ac- 
ceptable armor plate. 

As a supplementary topic of investigation,'^® the 
size effect in slow bend testing of keyhole-notched 
bars was studied on one billet of SAE 4140 steel. 
Rather consistent relations were found between en- 
ergy absorbed per volume deformed in geometri- 
cally similar bars, the unit work to fracture drop- 
ping as the size increases from i/g in. to 2 in. in 
width, or as the hardness of quenched and tem- 
pered specimens increases from 250 to 450 Vickers. 

Although the notched bar fracture test, devel- 
oped and employed by the Army Ordnance Depart- 
ment, has proved fairly satisfactory as a criterion 
for rejection for both rolled and cast homogeneous 
armor, it has the weakness that its value depends 
so much upon the personal judgment of the in- 
spector that careful training is necessary before 
readings of the appearance of the fractures by the 
inspectors are interpreted alike. 

There is a belief, based on early observations by 
von Karman, that the stress wave resulting from a 
very high-velocity impact travels in a peculiar 
fashion so as to build up peaks of extremely high 
stress. This theory and the experimental work 
which attempted to evaluate these stresses and their 
distribution when the impact is produced by other 
than ballistic means is discussed under the subject 
of the behavior of metals under dynamic conditions 
in Section 9.3.2 of this report. The attainable velo- 
cities were so low that the questions remained un- 
answered. Pioneering experiments indicated only 
how great are the experimental difficulties and 
failed to advance the situation with respect to ar- 
mor plate much beyond the original statement of 
von Karman. The results of some experiments did 
not agree very closely with the theory. This served 


CONFIDENTIAL 


36 


ARMOR 


to emphasize the fact that the simplest way to attain 
explosive velocity is to use explosives. 

Work done by the Navy has indicated interesting 
possibilities in the use of a test on notched impact 
bars of the Izod type but larger than the conven- 
tional Izod bar, in which the bar is broken by an 
impact delivered by a bullet instead of by a low- 
velocity pendulum. The results are reported, not 
as the foot-pounds of energy absorbed, but as the 
bullet velocity that is just sufficient to fracture. This 
brings in higher velocities, although the stress raiser 
inducing fracture is not that produced by the pro- 
jectile. 

A preliminary method developed for the shock 
testing of welded armor plate joints by the use of 
a demolition explosive also showed promise as a 
nonballistic test for prime homogeneous armor. 
The work was conducted at Trojan Powder Com- 
pany on Project NRC-25 (OD-76) (NS-255), Direct 
Explosion Test for Welded Armor and Ship 
Plate.81' 82 

In one of the tests developed, a charge of closely 
controlled explosive, placed just where the impact 
is desired, is detonated in contact with the plate. 
This test detected differences in heat treatment of 
the armor, in welding technique, or in quality of 
weld as related to the welding electrode used.®^ 

This work included also the development of a 
point blank test. In testing armor, the impacts of 
the projectiles must be on or near the weld in order 
to determine the resistance of the weld to penetra- 
tion. With current ballistic testing methods, it is 
often necessary to fire many shots to get an impact 
in the desired location. Better positioning of im- 
pacts would be a boon. With modern methods of 
measuring projectile velocity, only a few inches of 
travel are required for a determination. A commer- 
cial “gun,” which shoots a projectile into a steel 
plate to a distance regulated by the charge, was de- 
signed long ago for embedding studs (for example, 
to attach a lifting device to the shell of a sunken 
submarine). With careful selection of the explosive 
and careful weighing and loading, the distance of 
penetration is under close control, which means 
that the velocity is accurately controllable. 

Combining these methods, a smooth-bore gun is 
loaded with a controlled charge which propels a 
piston to which is attached a projectile. This pro- 
jectile, for test of relatively thin plate, travels only 
a few inches, and the point of impact can be de- 


termined within 0.1 in. Thus a projectile can be 
directed at the exact spot it is desired to hit and 
propelled with an exactly known and measured 
velocity. 

There seems no reason why this method cannot 
be scaled up for testing heavy plate. The variables 
that impede ordinary ballistic testing would thus 
be avoidable and the way opened to secure accurate 
testing of armor and to obtain data for the corre- 
lation of actual ballistic resistance, determined at 
velocities that meet service conditions, with the re- 
sults of low-velocity notched-bar impact tests. Hazi- 
ness of the claimed correlation between low-velocity, 
low-temperature impact results and ballistic test 
results is at present ascribed to the deficiencies of 
the ballistic test. Since with the above-described 
method the point of impact is under control, the 
area of the armor plate to be tested can be smaller. 
Therefore, cooling the armor to subnormal temper- 
atures for evaluation of low-temperature behavior 
and for direction comparison with low-temperature 
impact tests becomes more feasible, and a field is 
opened up which obviously requires intensive 
tilling. 

The direct explosion test is also discussed in Sec- 
tion 6.1.2 of this report in connection with the test- 
ing of welded armor and ship plate. 

23 INVESTIGATIONS ON 

IMPROVEMENTS IN ARMOR PLATE 

The majority of the Division 18 investigations on 
armor plate had to do with improving the proper- 
ties of armor plate compositions in existence at the 
initiation of the program and with seeking to reduce 
their alloy contents. One of the basic objectives of 
the work was to save strategic alloying elements at a 
time when their scarcity made it imperative that 
the utmost attention be given to the production of 
high-quality armor steel with a minimum expen- 
diture of alloys. Later, as the scarcity of alloying 
elements eased, the emphasis was directed toward 
possible improvements in the general quality of 
armor through further studies of such variables in 
heat treatment, structure, composition, and manu- 
facture as are likely to influence the ballistic be- 
havior of armor. While the work in its early stages, 
exclusively concerned armor under 2 inches in thick- 
ness, the protection of much heavier mechanized 
equipment which developed as the war continued 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


37 


made it necessary to focus attention on armor in 
thicknesses up to 6 inches. 

The various phases of research with respect to 
improvements of armor involved both face-hard- 
ened and homogeneous types. The work fell within 
the following three principal divisions: 

1. Face-hardened armor. 

2. Low-alloy homogeneous armor steel. 

3. High-alloy homogeneous armor steel. 

2.3.1 Face -Hardened Armor 

The regular methods by which armor plate is 
given a hard penetration-resistipg face and a tough, 
spall-resisting back are by carbuirizing the face, heat 
treating for diffusion to secure a desired carbon 
gradient, then quenching and tempering. These 
methods are time consuming. Quicker methods and, 
of course, better armor were eagerly desired. Sev- 
eral projects under the sponsorship of NDRC dealt 
with face-hardened armor. 

Experiments were conducted at the Massachu- 
setts Institute of Technology under Project NRC- 
23 (OD-88), Determination of the Effects of Flame 
Hardening on the Ballastic Properties of Pre-Heat- 
Treated Homogeneous Armor Plate, to study the 
effects on ballistic properties of flame hardening 
one face of homogeneous armor of accepted compo- 
sition and to compare these properties with those 
obtained on similar thicknesses of carburized plate. 
Flame hardening was accomplished by heating one 
face of the plate very rapidly with a very hot flame, 
thus producing a temperature gradient of such 
magnitude that, on quenching, a hard surface was 
obtained, leaving the center and the opposite face 
of the plate in their original condition. The vari- 
ables investigated were thickness of plate, depth of 
hardened layer, the effect of overlap, post-heat treat- 
ment, and distortion of plate. A somewhat similar 
program was carried out by flame softening as 
quenched fully hardened homogeneous armor in 
order to obtain a greater depth of hardened metal 
than was possible by flame hardening.®^ 

An improvement in the ballistic limit of i/^-in. 
armor was produced by flame hardening, but warp- 
ing was excessive. In 1-in. plate there was less dis- 
tortion and the ballistic resistance against projec- 
tiles striking head on was improved, but for oblique 
impacts it was decreased. A decrease in ballistic re- 


sistance was found in 1 i/ 2 -in. plate. It was therefore 
concluded that flame-hardening i/ 2 -in. plate was 
impractical, that flame-hardened 1-in. plate af- 
forded insufficient overall improvement to warrant 
its use on combat vehicles, and that flame-harden- 
ing iy 2 -in. plate was injurious. 

Flame softening, a practice which consists of tem- 
pering with a hot flame the back side of a quench- 
hardened plate in order to obtain a softer condition 
on the back than on the front, produced less dis- 
tortion in 1 / 2 -in. plate, and the ballistic results ap- 
proached those of regular i/ 2 -in. face-hardened 
armor. In 1-in. flame-softened plate, there was little 
distortion, and plates tested with caliber 0.50 AP 
M2 projectiles at normal impact were as good as the 
usual carburized face-hardened armor. In li/^-in. 
plate, it does not appear feasible to soften in this 
manner a depth sufficient to avoid back spalls. 

Thus flame softening appears better than flame 
hardening. Flame softening may be useful on i/ 2 -in. 
armor if some warping is not objectionable. It ap- 
pears to have distinct possibilities for 1-in. armor, 
although the process does not seem applicable to 
plate much thicker than 1 inch. 

Another method of producing hard surface on 
plate without changing its composition was investi- 
gated by the Buick Motor Division of General 
Motors Corporation on Project NRC-24 (OD-74), 
The Development of a Process for Manufacturing 
and Welding Face-Hardened Armor Plate. In this 
method, two plates placed back to back were 
welded together around the edges, heated to the 
quenching temperature, quenched in brine, tem- 
pered at 400 F, and then cut apart. Steels were 
chosen of such hardenability that only the faces of 
the plates toward the quench were hardened, while 
the backs remain unhardened. A simultaneous ob- 
jective of this investigation was to use steel of plain 
carbon composition in which the hardenability is 
regulated by raising the manganese content as the 
plate thickness is increased, and, in order to use as 
little manganese as possible, to induce hardenabil- 
ity by the use of boron in finishing of the heat, thus 
conserving critical alloys. 

Encouraging results, initially obtained for two 
small 1 / 2 -in. plates of 0.40% C, 0.85% Mn, and 
0.20% Si boron-treated steel, were the basis for an 
arrangement to investigate the proposed differential 
quenching process. Attempts to produce plates of 
the size required for ballistic testing produced dif- 


CONFIDENTIAL 


38 


ARMOR 


ficulties and discordant results, neither i/g-in. nor 
1-in. differentially quenched plate being produced 
in these larger sizes that passed ballistic require- 
ments. Few approached the requirement as to resis- 
tance to penetration, and, in those which did, back 
spalling was excessive. It was finally concluded that 
the pearlitic structure of the unhardened back of the 
plate was inherently unadapted to resist spalling.^^ 

The Buick Motor Division on Project NRC-30 
(OD-74), Development of Processes for the Manu- 
facturing and Welding of Case-Carburized Armor 
Plate from Non-Alloy Steels, also investigated a 
process for case-carburizing armor plate in an effort 
to develop satisfactory armor with the use of boron- 
treated plain carbon or low-alloy steels. 

In this investigation, gas carburizing with proper 
control of the carburizing atmosphere was used to 
produce a lower carbon case than is normally ob- 
tained by carburizing with solid carburizers. A wide 
variety of case depth and modifications in carburiz- 
ing times and diffusion times were investigated. At 
the time this research was undertaken, the conser- 
vation of critical alloying elements was still highly 
important, so the use of manganese and boron treat- 
ment or of some of the low-alloy National Emer- 
gency [NE] steels, whose alloy content is derived 
chiefly from scrap, were studied. The work was con- 
centrated on light armor. The steels chiefly used 
were the plain carbon type with 0.16% C, 0.76% 
Mn, boron-treated, and the NE 94T20 type contain- 
ing 0.20% C, 1.0% Mn, 0.50% Si, 0.30% Ni, 0.30% 
Cr, and 0.10% Mo with boron treatment. 

The latter steel, gas carburized and then given a 
diffusion treatment in a neutral atmosphere, had a 
carbon content of about 1 per cent at the face, with 
the case depth extending about half the thickness 
of %-in. plate. Such plate gave ballistic results 
equivalent to those required for somewhat thicker 
plate with no spalling. These promising results led 
to an extension of the work to aircraft armor and 
ammunition test plate using %-, %-, i/^-, and ^-in. 
thicknesses, the steel chosen being NE 86T17 type 
(0.17% C, 0.80% Mn, 0.30% Si, 0.15% Ni, 0.50% 
Cr, 0.20% Mo, boron-treated). After gas carburizing 
and tempering at 325 F for 2 hours, all the plates 
showed excellent resistance to penetration but were 
marginal in shock test. 

A series of regular commercial-grade face-hard- 
ened armor plate with about 4 per cent nickel and 
another series of plates of NE 86T17 and 86T20 


steel were prepared and sent to Aberdeen Proving 
Ground for testing at normal and sub-zero temper- 
atures. Both series had plate in the four thicknesses 
mentioned above with case depths of 25 and 40 per 
cent of the plate thickness. The results of the room- 
temperature test indicated that with the NE 86T17 
and 86T20 analyses satisfactory resistance to pene- 
tration can be obtained, but the general shock 
and penetration-through-plate characteristics were 
either borderline or definitely below the require- 
ments of Specification ANOS-2. The low-tempera- 
ture test brought about a very marked decrease in 
the shock properties of this armor with plates fail- 
ing to meet ballistic requirements by more than 
700 fps. 

On the other hand, regular commercial-grade 
face-hardened armor gave excellent shock and pene- 
tration through plate results at both normal and 
sub-zero temperatures. Their resistance to penetra- 
tion also was fairly high for this steel. 

It appears that the NE 86T17 and NE 86T20 
steels are not suitable for processing armor under 
Specification ANOS-2 using the treatment em- 
ployed. ^ 5, 86 

In somewhat analogous fashion, work was con- 
ducted at Battelle Memorial Institute aimed at in- 
creasing the toughness of the case on face-hardened 
armor by holding down the surface carbon in ordi- 
nary pack carburizing.^^ This work was part of 
Project NRG- 14 (OD-87), Improvement of Low- 
Alloy Armor Steels. Some earlier work suggested 
that additions of ferrosilicon to the carburizing 
compound would result in lower surface carbon in 
the case. In tests of this on armor steels, erratic 
results were obtained, and it appeared that the fer- 
rosilicon was acting as a diluent just as so much 
magnesia or silica flour does. However, when 
both ferrosilicon or silicon carbide and certain 
chlorides, especially nickel chloride or chromium 
chloride, were added, a reduction in surface carbon 
was obtained. The chlorides alone were energizers, 
and in 8 hours at 1700 F carburizing without the 
silicon compound they produced surface carbon 
contents of 1 to 1.10 per cent. With the silicon com- 
pound, the surface carbon could be held down to 
0.45 to 0.90 per cent carbon as desired. 

In effect, this process eliminates the need for a 
diffusion treatment to lower the maximum carbon 
content of the case after the carburizing cycle. Since 
appreciable lowering of the carbon content can be 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


39 


accomplished without reducing the hardness of the 
case, it is thus conceivable that the ductility and 
toughness of the case could be decidedly improved 
without any sacrifice of ballistic properties. No bal- 
listic tests were carried out, however, on plates so 
carburized. 

2 3-2 Low-Alloy Homogeneous Armor Steel 

As part of Project NRC-14, Improvement of Low- 
Alloy Armor Steels, the literature and patents were 
surveyed for information regarding the use of small 
additions of various elements or alloys to improve 
certain qualities of steel. The object of this survey 
was to determine whether or not any of these mate- 
rials could be used to improve the ballistic proper- 
ties of the armor steels or to reduce their alloy 
content with no reduction in ballistic properties. 
As a result of this survey, a large number of tests 
were made of various additions. A list of these ad- 
dition agents includes boron, aluminum, silicon, 
tellurium, calcium, selenium, titanium, Columbian, 
lithium, zirconium, nitrogen, and a number of pro- 
prietary alloy additions of complex analyses. ^8, 89, 
90,91 

Outside of the boron addition, none of the treat- 
ments were outstanding in their effects, although 
several of them contributed minor improvements. 
Zirconium, for instance, gave a definite boost to the 
depth hardening properties, although it seemed to 
decrease the notched bar toughness. On the basis of 
these preliminary tests, it was decided to discon- 
tinue further study on all other treatments and to 
concentrate on an investigation of boron in armor 
steels. 

Investigation of Boron in Armor Plate 

The amount of boron required to increase mate- 
rially the hardenability of an already somewhat 
hardenable steel is almost unbelievably small. The 
proper amount to add is considered never to be 
over 0.007 per cent. Peacetime commercial experi- 
ence with boron steels was sufficient to justify much 
hope but too meager to supply all of the answers to 
the questions that must be answered before the 
boron-treated steels could be adopted for armor. 
Not all attempts to confer hardenability by boron 
treatment were successful. The mechanism by 
which boron confers hardenability is not under- 
stood, and, while the conventional metallurgical 


tests for mechanical properties had been made on 
many boron-treated steels that were mechanically 
equivalent to more highly alloyed steels without 
the treatment, there was little experience with them 
in various types of severe service, and none at all 
in armor. The various unknowns in respect to 
boron-treated steels, therefore, became the basis for 
investigations to determine the actual possibilities 
and limitations of these steels in order to establish 
confidence in their use. The problems directly re- 
lated to armor were of great interest to the Army 
Ordnance Department, and several projects were 
set up to bring out the unknown facts. 

A study of the influence of boron on some of the 
properties of experimental and commercial steels 
was carried out at the National Bureau of Stand- 
ards under Project NRC-31 (OD-87), Investigation 
of Boron in Armor Plate. The results of this inves- 
tigation are summarized in a series of progress re- 
ports covering a period of two years of work on the 
following subjects: 

1. Influence of variations in boron, carbon, and 
manganese contents on some properties of steels for 
armor plate and other military applications.®^ 

2. Influence of variations in boron, carbon, and 
manganese contents on the weldability of steel for 
armor plate and other military applications.®® 

3. Influence of nitrogen on some properties of 
steels with and without boron and titanium addi- 
tions.®^ 

4. Influence of variations in boron, composition 
of ferro-alloys used for making boron additions and 
deoxidation practice on some properties of experi- 
mental steels containing 0.3% carbon and 1.6% 
manganese.®® 

5. Influence of boron and nickel on some proper- 
ties of experimental steels containing 0.3% carbon 
and 0.8% manganese.®® 

6. Influence of boron and chromium on some 
properties of experimental steels containing 0.3% 
carbon and 0.8%, 1.25%, or 1.6% manganese.®^ 

7. Influence of nitrogen on some properties of 
experimental steels without and with boron.®® 

8. Influence of boron on some properties of ex- 
perimental steels containing nickel and chromium.®® 

9. Influence of variations in boron and composi- 
tion of ferro-alloys used for making boron addi- 
tions on some properties of basic open-hearth steels 
containing 0.4% carbon and 1.6% manganese. 

The final report on this project covered an in- 


CONFIDENTIAL 


40 


ARMOR 


vestigation of boron in armor plate dealing with the 
influence of boron on some properties of experi- 
mental steels containing 0.3% carbon and varying 
amounts of manganese, chromium, and molyb- 
denum. 

Tests were made on approximately 250 experi 
mental and 20 commercial steels. All of the experi- 
mental steels were prepared at Battelle Memorial 
Institute on Project NRC-31A. In the work at the 
National Bureau of Standards it was shown that 
variations from nil to 0.006 per cent boron addi- 
tions made with intensifiers either with or without 
grain refining elements had no significant influence 
on the following properties of the steels: (1) clean- 
liness, (2) hot working, (3) transformation tempera- 
tures, (4) resistance to softening by tempering, and 
(5) tensile strength when the steels were fully hard- 
ened and tempered, except possibly in improve- 
ment in ductility when tempered at low tempera- 
tures. Although boron lowered the coarsening tem- 
perature of austenite, steels with relatively high 
additions of boron could be rendered fine grained 
at heat-treating temperatures by the judicious use 
of grain-growth inhibitors such as aluminum, titan- 
ium, zirconium, and vanadium. It was shown that 
the influence of boron on hardenability and notch 
toughness varied with the base composition of the 
steels, the composition of the intensifiers, and the 
amount of boron present. Small amounts of boron 
were often beneficial to notch toughness at room 
temperature when the steels were fully hardened and 
tempered at low temperatures. When tempered at 
high temperatures, however, the presence of boron 
in steel, especially when added in relatively high 
amounts as intensifiers containing titanium, was 
usually either without effect or was detrimental to 
notch toughness at room and sub-zero temperatures. 

The hardenability of many of the experimental 
steels prepared in an induction furnace and of all 
the steels comprising a basic open-hearth heat was 
markedly improved by additions of boron. How- 
ever, no definite correlation was found between the 
hardenability effect and the amount of boron added 
or retained in the steels. In many of the experimen- 
tal steels, the optimum hardenability was obtained 
with small additions of boron (0.001 per cent or 
less), while in other steels the hardenability in- 
creased continuously with increasing boron content. 
In still other steels, the addition of boron, either as 
a simple or as a complex ferro-alloy or intensifier, 
was without effect on hardenability. In general, re- 


latively small additions were more effective than 
large. The complex intensifiers were more effective 
than the simple ones, and the improvement in 
hardenability was not so critically dependent upon 
the amount present when the additions were made 
with a complex intensifier. 

The effectiveness of boron in improving the hard- 
enability of the experimental steels increased with 
increased amounts of elements that conferred deep 
hardening properties, such as manganese, chrom- 
ium, and molybdenum. 

A progress report on the endurance properties of 
basic open-hearth steel containing 0.4% carbon and 
1.6% manganese without and with boron additions 
contains the results of additional work done at Bat- 
telle Memorial Institute on Project NRC-31A. This 
reportio 2 covers the endurance properties of three 
steels from the special commercial addition agent 
Heat No. 126405, Army Research and Development 
No. R.A.D.-1448. Two of the steels were treated in 
the mold with proprietary boron-containing alloys, 
while the third was a reference steel from the same 
heat containing no boron. This work was designed 
to supplement that conducted at the National Bu- 
reau of Standards on physical properties of steels 
from the same heat which was summarized in a prog- 
ress report cited earlier.ioo The endurance properties 
of boron-treated steel were comparable to those of 
the reference steel when tempered to the same hard- 
ness value, thus indicating that boron had no meas- 
urable effect on the endurance properties. 

Further information on boron is contained in a 
War Metallurgy Committee advisory report entitled 
Boron in Steel.^^^ This report is a very interesting 
presentation of the state of the knowledge in this 
field in 1942. It contains a comprehensive statement 
of the history of the use and effect of boron in steel. 

A final report on the improvement in low alloy 
armor steels dealing with boron in steel of armor 
composition, 104 contains also the results of an inves- 
tigation of boron as an alloy in steel. The investiga- 
tion was part of the program of Project NRC-14 
(OD-87) and covered the use of boron in armor steel 
but more specifically its use as a substitute for molyb- 
denum. About the time the work got under way, 
the use of molybdenum was drastically restricted, 
and it seemed appropriate, in view of the proba- 
bility of a continued shortage, to limit the investi- 
gation of boron as an alloy to its possible use as a 
substitute for molybdenum. The results show that 
boron can be substituted for a much larger quan- 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


41 


tity of molybdenum as far as hardenability goes, 
but it does not have the specific effect of molybde- 
num in mitigating temper brittleness. It does not 
lower the critical temperature and the quenching 
temperature as nickel does, but that is not very im- 
portant. On the whole, amounts of nickel, molyb- 
denum, and chromium well worth saving can be 
replaced by a tiny amount of boron on the basis of 
mechanical test results. 

The presumption is, therefore, that the much de- 
sired avoidance of slack quenching in the interior 
of relative heavy armor can be achieved by boron 
treatment up to thicknesses that would require ex- 
cessive amounts of the usual alloying elements. 
Depending somewhat upon the quenching tech- 
nique, there is, of course, a maximum thickness be- 
yond which no combination of elements, whether 
or not assisted by boron, can achieve avoidance of 
slack quenching, and structures less desirable than 
tempered martensite have to be put up with. How 
useful boron may be in very heavy armor that can- 
not be given any but a slack quench structure re- 
mains to be evaluated. 

The use of boron in steels suitable for 3- to 6-in. 
cast armor was also investigated.i<^» A fairly com- 
prehensive testing program was conducted on mate- 
rial cast into 6-in. plate to investigate the use of 
boron in steels of armor composition and to deter- 
mine the effects of variations in deoxidation treat- 
ment on the boron effect. Boron did enhance the 
hardenability of these steels without increasing 
their susceptibility to quench cracking or to temper 
brittleness, and, so far as could be determined, con- 
ferred no undesirable characteristics. A deoxidation 
treatment with aluminum seemed to give consis- 
tent and better results than were obtained when 
titanium was used prior to the boron addition. 

The studies of the use of boron for reducing the 
alloying elements in armor steel without sacrificing 
ballistic properties bore out the fact that armor 
with relatively low alloy content but with the 
boron treatment would be equivalent to armor 
richer in alloy content. 

An inquiry to Watertown Arsenal brought out 
the fact that boron additions used by some produc- 
ers had not been consistently reported, but that in 
so far as segregation can be made, i/^-in. and 1 i/^-in. 
rolled homogeneous armor steels with higher molyb- 
denum and no boron and those with lower molyb- 
denum and a boron addition are indistinguishable 
in ballistic tests. Some producers of rolled armor 


made effective voluntary use of boron to insure 
hardenability in alloy-poor compositions that would 
otherwise be on the borderline of hardenability. 
With the information now available, a much greater 
saving of alloy than was actually accomplished 
would now be feasible. Producers of cast armor do 
not seem to have made much use of boron, as their 
understanding of its use seems, in general, to be 
less than is the case with steel mills. 

As a further step toward conserving strategic al- 
loying elements by employing boron in alloy-free 
or low-alloy steels, the Buick Motor Division of 
General Motors Corporation carried out Project 
NRC-29, Development of Processes for the Manu- 
facturing and Welding of Homogeneous Armor 
Plate from Non-Alloy Steels. The basic idea again 
was the saving of strategic alloying elements by us- 
ing alloy-free or low-alloy steels whose hardenabil- 
ity had been augmented by boron treatment. The 
project dealt with homogeneous plate from i/4 in. 
to 1 in. thick, both in the machinable and high- 
hardness grade. 106, 107 

Using steel of about 0.27% carbon, 1.15% man- 
ganese, plus an addition of boron, it was 
found possible to produce i/^-in. plate with satisfac- 
tory ballistic performance, but it was difficult to 
secure both resistance to penetration and freedom 
from spalling. Commercial variations in hardenabil- 
ity made it doubtful if uniformly high quality could 
be readily maintained in production. Attention 
was, therefore, shifted to steel with a greater mar- 
gin of hardenability, such as steel with 0.45% 
carbon, 1.5% manganese, which was boron treated. 
Satisfactory i/^-in. and ^-in. plates were produced 
from this steel, but a higher resistance to penetration 
would have been desirable. When the scrap situation 
became favorable for making the triple alloy type 
of National Emergency steel, attention was centered 
on the NE 9430 type without and with boron treat- 
ment. The non-boron-treated NE 9430 steel gave 
satisfactory i/^-in. plate, and the boron-treated steel 
of the same type gave satisfactory 1-in. plate. These 
steels were later put into production. 

Investigations on the Effects of Gaseous 
Elements in Armor Plate 

Although it is known that the common gases, 
nitrogen and hydrogen, may have a material effect 
on the quality of steel, analysis for these elements 
is seldom made because of difficulties involved in 
the analytical method. In armor plate, where every 


CONFIDENTIAL 


42 


ARMOR 


means of improving quality is of paramount impor- 
tance, the role played by the gases becomes of spe- 
cial interest. Obviously, any information leading to 
a greater appreciation of the importance of oxygen, 
nitrogen, and hydrogen would ultimately lead to 
better armor.^^® This problem was recommended 
for study by the NDRC ad hoc Committee on Ar- 
mor Plate. Therefore in Project NRC-4 (OD- 
38-2), Effects of Hydrogen, Nitrogen and Oxygen in 
Armor Plate, established at Battelle Memorial Insti- 
tute, it was planned to make a study of these gases 
from the standpoint of their inffuence upon ballistic 
properties. One of the methods used to attack this 
problem was to carry out direct analyses of armor 
plate samples in an effort to obtain some correlation 
between the gas content and ballistic properties. A 
considerable number of fractional vacuum fusion 
analyses were made on rolled and cast commercial 
armor plate representing ballistically satisfactory 
and unsatisfactory material.i^^ Neither hydrogen 
nor nitrogen values could be correlated with ballis- 
tic properties. It was found that rolled plate which 
failed because of back spalling tended to have 
higher oxygen content than satisfactory plate. In 
cast steels, the oxygen content was found to be 
roughly related to inclusion type. Cast plates of low 
oxygen content generally contained duplex sul- 
phides. When the oxygen content was relatively 
high, the inclusions were globular silicates and sul- 
phides. The network or eutectic-type inclusions 
which lead to inferior ductility, low notch tough- 
ness, and generally poor ballistic properties pre- 
vailed when intermediate oxygen contents were en- 
countered. Residual aluminum contents were found 
to vary inversely with the total oxygen values as 
would be expected from the nature of the non- 
metallic inclusions. 

In early studies on this project, a peculiar inter- 
crystalline type of fracture was observed in several 
samples of commercial cast armor. It was noted that 
the elongation and reduction of area values of steel 
exhibiting this type of fracture were abnormally 
low, which is tantamount to saying that the steel 
had poor ballistic properties. The contour of a frac- 
ture suggested that the failure occurred through 
regions that were originally the primary austenite 
grain boundaries. Careful examination of a sample 
under the microscope revealed the presence of a 
chain of nonmetallic particles which were extremely 
small in size and became apparent only at magni- 


fication of 1,000 diameters or more. The aluminum 
content of the steel was noted to be somewhat 
greater than normally found where aluminum is 
used simply for the purpose of deoxidation. Fur- 
thermore, analyses showed that the steel contained 
a higher than normal nitrogen content. Experi- 
ments were undertaken which gave conclusive evi- 
dence that the presence of aluminum nitride was 
the cause of the intergranular precipitate in the 
samples of commercial armor examined.^i^ The 
amount of the intergranular precipitate found in 
the steel increased with the amount of aluminum 
used for deoxidation, with the nitrogen content of 
the melt, and with a decrease in the cooling rate 
following casting. 

As the experimental work on improvement in ar- 
mor proceeded, additional examples of intergran- 
ular fractures were received from various producers 
of armor plate, and, upon their examination, it be- 
came apparent that a number of different conditions 
could cause such fractures. Various causes of inter- 
granular fracture met with on Project NRC-14 are 
presented in a report on the causes of intergranular 
fracture in cast armor plate. The following causes 
are now recognized: (1) aluminum nitride precipi- 
tation at the primary grain boundaries, (2) ferrite 
precipitation as a network at the primary grain 
boundaries, (3) massive carbides in the primary grain 
boundaries, (4) extreme cases of Type II sulphide 
inclusions, and (5) internal hot tears. Of these, the 
prime cause was found to be aluminum nitride pre- 
cipitation at the primary austenite grain boundaries. 
The information found in these investigations was 
used in overcoming intergranular fracture problems 
in a number of foundries producing cast armor. 

Investigations of Structure in 
Homogeneous Armor 

During the early periods of World War II, ques- 
tions arose as to the effect on ballistic properties of 
the various structural constituents formed during 
the quenching of armor plate. Investigations soon 
showed that the effectiveness of the quench was all 
important. Examination of a large number of speci- 
mens of commercial armor plate revealed that some 
producers did not always obtain full hardening, 
with the result that some ferrite, pearlite, or bainite, 
or combinations of these constituents were present 
after the quench. At the recommendation of the 
NDRC ad hoc Armor Plate Committee^® a study 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


43 


was undertaken at Battelle Memorial Institute with 
the intention of determining the effects of micro- 
structure on the ballistic limit and shock resistance 
of armor plate. This work constituted the program 
for Project NRC-5 (OD-83), Correlation of Metal- 
lographic Structures and Hardness Limit in Armor 
Plate. The final reports on this project covered the 
effects of austenite transformation products on bal- 
listic properties,^ the correlation of microstruc- 
ture and ballistic properties, and analyses of 
problems presented by individual producers.^^^ 

In a study of the effects of austenite transforma- 
tion products on ballistic properties, i^-in. rolled 
armor from a single heat was received and was 
given the three general types of heat treatment: (1) 
full quench followed by tempering to the desired 
hardness, (2) intercritical quench followed by tem- 
pering to the desired hardness, and (3) subcritical 
quench in molten lead. After heat treatment, the 
plates were sent to Watertown Arsenal for ballistic 
testing and were then returned for physical testing 
and metallographical examination. While, for a 
given hardness, ferrite was shown to have no effect 
on the ballistic limit, it lowers the resistance to back 
spalling and causes back spalling to occur at a low 
hardness value. Plates which were isothermally 
treated to produce bainite and a small amount of 
uniform network of ferrite have higher ballistic 
limits for a given hardness than fully quenched and 
tempered plate. The fact that isothermal quenching 
of armor has a serious limitation in that it can be 
applied at the present time only to thin plate is dis- 
couraging to any attempt to develop isothermally 
transformed armor plate commercially. 

In connection with the correlation of microstruc- 
ture and ballistic properties, metallographic speci- 
mens from a large number of cast and rolled 
ballistic test plates ranging from 1 to 2 in. in thick- 
ness were carefully examined from surface to core 
to note the character of the matrix structure and 
the inclusions. Examples of both acceptable and 
unacceptable plates were represented. This investi- 
gation disclosed that failure by cracking occurs 
most frequently in plates having excessive amounts 
of free ferrite or excessive hardness, but that crack- 
ing failures are reduced when the ferrite is fortified 
by such ferrite strengtheners as copper or silicon. 
Hardenability data indicated that poor queiiching 
technique is an important factor in the appearance 
of free ferrite. 


In addition to excessive ferrite, nonhomogeneous 
microstructure and excessive amounts of porosity or 
nonmetallic inclusions were shown to be undesir- 
able and detrimental to ballistic properties. 

Attempts to produce, by controlled heat treat- 
ment, various types of metallographic structures in 
plates substantiated evidence that, for ease of manip- 
ulation and best results, a full quench followed 
by tempering to the desired hardness gave the best 
type of microstructure for resistance to ballistic 
penetration and shock. 

In examining a limited number of spalled and 
cracked plates of rolled armor, it was observed that 
the spalled plates contained much larger oxide in- 
clusions than either the cracked or satisfactory 
plates, while banding also was found in many of 
the spalled plates. On the other hand, cracked 
plates showed a much greater drop in notched-bar 
toughness when the testing temperature was low- 
ered from room temperature to —40 F than did 
either the spalled or satisfactory plates. The cracked 
plates contained much more ferrite at the core and 
were softer at the core than the satisfactory plate, 
whereas the spalled plates held a position interme- 
diate to the satisfactory and cracked plates with re- 
spect to hardness and ferrite contents of the core. 

Inasmuch as proper microstructure is a requisite 
for good armor plate, the extent to which heat 
treating variables affect the microstructure and 
mechanical properties of low-alloy armor steel was 
investigated under Project NRG- 14 (OD-87), Im- 
provements of Low-Alloy Armor Steels. 

The purpose of the study was to determine the 
importance of heating rate, holding temperature, 
and holding time prior to the quench, and cooling 
rate during the quench on the microstructure and 
properties of 2-in. cast armor. Variations in heating 
rates, holding time, and holding temperature were 
found to be of little consequence in regard to aus- 
tenitizing the steels and getting uniformity of tem- 
perature through the cross section, provided the 
holding temperature was above the Acg tempera- 
ture for the composition. Undesirable microstruc- 
tures appeared more likely to form as the result of 
improper handling in the quench. 

Tensile test bars that were heat treated to pro- 
duce 100 per cent martensite in the quenched struc- 
ture as well as being heat treated to other types of 
structure indicated that the best combination of 
strength and ductility is obtained in those bars con- 


CONFIDENTIAL 


44 


ARMOR 


sisting of 100 per cent martensite. Any variation of 
this structure resulted in lower ductility with the 
decrease in ductility being proportional to the 
amount of ferrite present in the microstructure. In- 
creasing the holding time and holding temperature 
was found to be beneficial in the case of steels con- 
taining carbides which inherently are difficult to 
dissolve in austenite.^^ 

Heat Treatment and Mechanical Properties of 
Low-Alloy Homogeneous Armor 

It was common practice to homogenize the hetero- 
geneous coarse-grained structure developed dur- 
ing the solidification of homogeneous cast armor 
on the assumption that the treatment refined the 
grain, diffused segregated areas resulting from the 
dendritic mode of freezing, and improved the me- 
chanical properties, particularly ductility and tough- 
ness. The homogenizing heat treatment is generally 
carried out at temperatures considerably higher 
than those used for normal heat treating practice, 
but there was no consistency among producers of 
cast armor in regard to either the temperature or 
the holding time at temperature used. It was not 
unusual to find one steel foundry homogenizing at 
1700 F for 4 hours and another at 2000 F for 10 
hours for castings of the same section size. The im- 
plication derived from this decided lack of uniform- 
ity in homogenizing heat treating practice was that 
there is no unanimity of opinion in the cast steel 
industry regarding the value of homogenizing. If 
it were true that a drastic heat treatment of many 
hours at high temperature is necessary, then those 
who employed lower temperatures and shorter 
holding times were not realizing the maximum 
properties from their armor. On the other hand, 
if there were no particular advantage in going to 
higher temperatures and longer holding times, or 
if the advantage was so slight that a minor adjust- 
ment in composition would compensate for it, then 
the drastic heat treatment could be curtailed in 
order to save time and heat treating capacity. 

When the immediate importance of this problem 
to the cast armor producers was recognized, an 
extensive survey of the homogenizing heat treat- 
ment was undertaken at Battelle Memorial Institute 
as part of Project NRC-14 in order to obtain a 
better understanding of the value of homogeniza- 
tion and to accumulate data that would be useful 
to the cast steel producers in governing their heat 


treating practice. Cast armor plates submitted by 
five producers were examined carefully after being 
given various homogenizing heat treatments. 

No significant effects or trends from the homo- 
genizing treatment were observed on the austenitic 
grain size, hardenability, notched bar toughness, 
or V-notched Charpy at room and subatmospheric 
temperatures, temper brittleness susceptibility, oi 
tensile properties. The properties of unhomogen- 
ized specimens were generally equivalent to those 
from homogenized material. Successive increases in 
homogenizing temperature or holding time brought 
about a gradual diffusion of the dendritic pattern on 
etched macrospecimens. However, even the most 
drastric heat treatment did not obliterate this struc- 
ture. It was generally concluded that, in the steels 
examined, the various homogenizing treatments 
produced no appreciable change in the characteris- 
tics of the hardened and tempered specimens and 
that true homogenization can be effected only by 
holding the steels at temperature in excess of 2200 F. 

On the other hand, work described in a report 
on the causes of quench cracking in cast armor 
steePi^ showed that a decrease in quench-crack sus- 
ceptibility accompanied the substitution of homo- 
genizing pretreatment for a normalizing treatment. 
A homogenizing treatment of 8 hours at 2300 F was 
particularly effective in decreasing the quench-crack 
susceptibility. 

In line with the investigation of quench cracking 
in cast armor steel, a test was developed for mea- 
suring the quench-crack susceptibility of fully 
hardened cast armor plate. Quench-crack suscep- 
tibility as measured by the test was influenced 
greatly by the composition of the armor. Steels with 
less than 0.25 per cent carbon seemed not to be 
immune to quench cracking, but quench-crack sus- 
ceptibility increased rapidly as the carbon content 
increased from 0.25 to 0.35 per cent. Quench-crack 
susceptibility also increased with increasing nickel, 
chromium, manganese, and phosphorus contents, 
but no effects were observed for variations in silicon, 
sulphur, molybdenum, or boron contents, or in the 
percentage of added aluminum. On the other hand, 
increases in the time at the austenitizing tempera- 
ture and a decrease in the quenching temperature 
reduced the quench-crack susceptibility. 

Tw(f possible factors influencing quench-crack 
susceptibility of steels are the temperatures at which 
martensite is formed and the amount of expansion 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


45 


involved in the transformation to martensite. To 
investigate this point, an attempt was made to de- 
velop a dilatometer which would be sufficiently fast 
and sensitive enough to show the temperature and 
expansion of the martensite transformation. This 
investigation was part of Project NRC-14, and the 
results are described in two reports on the determi- 
nation of martensite transformation points^i® and 
the continuation of dilatometric studies of armor 
with respect to quench cracking.n^ 

For this work, a high-speed dilatometer, using 
strain gages to register dilation, was designed and 
built. Difficulties with the drift of the zero point of 
the instrument and difficulties encountered with a 
switching device in the electrical circuit were obsta- 
cles to the satisfactory performance of the instru- 
ment. Martensite transformation points, however, 
were determined for a number of steels from cool- 
ing curves obtained with part of the dilatometer 
apparatus. 

In the production of the cast armor, it was recog- 
nized that variations in physical properties of steel 
are associated with melting and deoxidation prac- 
tice as well as with variations in heat treatment. 
Since no universal melting practice is employed 
among the foundries manufacturing cast armor, 
and since a number of foundries unacquainted with 
its production were encouraged to enter the field 
without adequate knowledge of the problems in- 
volved, investigations were undertaken under Proj- 
ect NRC-14 to assist the uninformed foundries by 
investigating some of the variables in melting prac- 
tice which have an effect on the quality of cast 
armor. Several types of melting practice were ex- 
amined in both acid-lined and basic-lined electric 
furnaces. The sulphur content itself or the sulphide 
distribution appeared to be the principal variable 
controlled by the melting operation which affected 
the physical and notched bar properties of the steel. 
When the sulphur content increased or the sul- 
phide inclusions were distributed along grain 
boundaries, the toughness decreased as it did also 
with increased amounts of inclusions and in the 
presence of the aluminum-nitride precipitate. As a 
general rule, acid cast steels were inferior in prop- 
erties to basic steels, though much of the difference 
probably resulted from the higher sulphur content 
in the acid steels. The hardenability of the steels 
examined was found to vary over a greater range 
than could be accounted for by their chemistry. On 


the average, cast steels were at lower hardenability 
than wrought steels of the same analyses.^!® 

The relationships between chemical composition, 
mechanical properties, tempering characteristics, 
and hardenability of cast steels of armor composi- 
tions was investigated by the American Brake Shoe 
Company under Correlation Project NRC-83A, 
Hardenability of Cast Steels for Use in Ordnance 
Materiel. This project was financed by the com- 
pany and carried out under the general supervision 
of the War Metallurgy Committee. The depth- 
hardening characteristics of the cast steels were de- 
termined, employing single and double end-quench 
tests to show the effect on hardenability of several 
alloying elements in several base compositions. It 
was pointed out, however, that other variables be- 
side compositional changes may effect inherent 
hardenability. In castings, for example, it was evi- 
dent that the cast section size may exert considerable 
influence. Melting and deoxidation practices also 
were considered significant, while segregation was 
recognized as a variable of particular importance. 

For all practical purposes, the data confirmed the 
hypothesis that different alloy combinations had 
little effect upon the usual mechanical properties 
of fully hardened and tempered cast steels. There 
was some indication that over alloying, as repre- 
sented by greater hardenability than needed for full 
hardening, may result in a slight impairment in 
properties, particularly by lowering the reduction 
of area. The influence of several alloying elements 
upon resistance to tempering also was examined in 
this investigation. As would be expected, the in- 
creased resistance to softening, evidenced by the 
higher temperature required to temper to a known 
Brinell hardness value, was associated with steels 
containing the strong carbide-forming elements, 
chromium and molybdenum. 

Producers of armor plate exercise a certain 
amount of choice in deciding the tempering time 
and tempering temperature to be used in meeting 
a hardness specification. The fact that different pro- 
ducers do make use of different practices in obtain- 
ing the same hardness in armor plate led to the 
question of whether any advantage in mechanical 
properties could be assigned to a particular tem- 
pering practice. Other questions arose as to effect 
on the mechanical properties, particularly notched 
bar strength and temper brittleness, of replacing 
molybdenum with boron. An investigation was un- 


CONFIDENTIAL 


46 


ARMOR 


der taken, therefore, as part of Project NRC-14, Im- 
provement of Low-Alloy Armor Steels, to study the 
effect of tempering practice on mechanical proper- 
ties of a number of low-alloy armor plate composi- 
tions. The steels tested were fully hardened and 
then tempered to within the range of about 200 to 
400 Brinell. The results are contained in one of the 
final reports. It was shown that tempering practice 
involving either time, temperature, or cooling rate 
after tempering does not effect either tensile 
strength, yield point, elongation, or reduction of 
area, except in so far as the tempering practice 
simultaneously affects the Brinell hardness.^^® An 
excellent correlation was observed between Brinell 
hardness and either tensile strength, yield point, or 
elongation, and a less pronounced though still good 
correlation was found to exist between Brinell hard- 
ness and reduction of area. 

Tempering practice had, however, a very definite 
effect on the V-notch Charpy values of those steels 
subject to temper brittleness. Short draw times fol- 
lowed by water quenching produced the best 
Charpy values in steels subject to temper brittle- 
ness. The Charpy values obtained for steels not sub- 
ject to temper brittleness, that is, steels containing 
0.40 per cent molybdenum, were observed to corre- 
late with Brinell hardness almost as well as did the 
tensile strength. 

Armor steel must retain a large percentage of 
toughness at sub-zero temperature. While the qual- 
ity of the steel and the heat treatment employed 
are known to have a large effect on this property, 
the alloy content of the steel must also be consid- 
ered. Nickel, for instance, has been advocated as a 
desirable element for promoting low-temperature 
toughness, particularly if used in amounts exceed- 
ing 11/2 per cent. Because some of the armor plate 
compositions currently used during the war did not 
contain nickel as one of the specified elements but 
often contained appreciable quantities of residual 
nickel brought in through melting scrap, considera- 
tion was given to the possibility of making good use 
of this residual nickel by adjusting its amount 
within a composition range that might contribute 
to the properties of the steel. The possibilities for 
obtaining some slight gain in the low-temperature 
toughness by employing nickel in such armor com- 
positions that normally do not contain nickel con- 
stituted part of the program. 

While quantities of nickel up to 1 per cent were 


employed in the manganese-molybdenum and the 
manganese-chromium-molybdenum low-alloy armor 
compositions in this investigation, no significant 
change in the toughness of these steels at low tem- 
perature as a result of the presence of nickel was 
found.121 

2.3.3 High-Alloy Homogeneous Armor Steel 

The attainment of a martensitic structure is not 
difficult normally provided sufficient alloy can be 
used, but because of past scarcities as well as for 
production and metallurgical reasons, the goal of 
100 per cent martensite after the quench has not 
always been an easy one to reach. In the early stages 
of armor plate research during the war, the lack of 
alloys and the restriction of the carbon content to a 
maximum of about 0.30 per cent to avoid quench 
cracks and welding failures required that the steel 
be handled skillfully to obtain full hardening with 
the chosen composition. Alloys could not be used 
promiscuously, and compositions assigned to the 
heaviest sections were too rich for use in lighter 
parts. In many ways though, the metallurgical prob- 
lems were straightforward, for, if the alloy require- 
ments of a plate of one size were known, it was not 
difficult to make use of a hardenability test and a 
knowledge of cooling rate to ascertain the alloy re- 
quirements for a plate of another size. In terms of 
the isothermal transformation curves, the nose of 
the S-curve would have to be displaced one way or 
another to assure adequate hardenability with mini- 
mum alloy content for the section concerned. 

These considerations were applicable to relatively 
light armor plate up to 2 inches in thickness. The 
fact that an analogous situation does not exist with 
armor plate of heavier sections is a basis of much 
research work covered during the latter part of 
World War II. Many complicating factors prevent 
the study of heavy armor plate from being similar 
in kind to that of the lighter sections. First of all, 
the cooling rates in the heavy sections are below the 
range of those considered heretofore for quench 
material. Consequently, it was necessary to deter- 
mine what these rates were. This was done by ex- 
trapolation of experimental results on sections rang- 
ing from 3 to 6 inches and by calculations making 
use of published tables on cooling rates in plates. 
A progress report on Project NRC-14, Improvement 
of Low-Alloy Armor Steels, summarizes the experi- 


CONFIDENTIAL 


INVESTIGATIONS ON IMPROVEMENTS IN ARMOR PLATE 


47 


mental work on heavy armor steels and records the 
experimental and calculated cooling rates at 700 F, 
1000 F, and 1300 F for plate thicknesses up to 10 
inchesd“ Details are given in an earlier report on 
the heating and cooling rates of heavy armor plate 
and the calibration of an air-cooled hardenability 
specimen.!-^ 

A somewhat analogous investigation was con^ 
ducted at the Research Laboratories Division, Gen- 
eral Motors Corporation, to determine accurate 
cooling rates at 1300 F between center and surface 
of various size rounds and plates when heated under 
different conditions of temperature and atmosphere 
and quenched in different media at various veloci- 
ties. The object of this investigation was to obtain 
a more accurate correlation of cooling rates of 
rounds and plates with those of the standard end- 
quench hardenability bar. While this project was 
not directed specifically toward armor plate re- 
search, nevertheless the field covered was of direct 
value in interpreting the effect of the massiveness 
of the section involved in the heat treatment of 
heavy armor plate. This work was conducted on 
Project NRC-55, Heat Treatment of National Emer- 
gency Steels for Use in Tanks, Combat Cars, Gun 
Mounts and Other Ordnance Materiel. The progress 
reports on this project contain a description of the 
scope of the project, the procedure, and equipment 
used,i24 a discussion of the cooling curve recorder 
with sample curves and the methods for analyzing 
sample curves and the methods for analyzing the 
the data,i25 and the cooling rates and cooling times 
in end-quench hardenability test bars of four steel 
compositions.^-® The final report^-^ summarizes 
all of the data on the project and contains cooling 
rates and cooling times for water-quenched rounds 
up to 4 inches in diameter and for 3-in. plate speci- 
mens of NE 9445 steel. This project is also discussed 
in Section 9.4.5 of this report. 

In the production of heavy armor plate, 4 in. in 
thickness and greater, a knowledge of the harden- 
ability required to produce full hardening at the 
center of such massive plates was desirable. A spe- 
cial type of hardenability specimen having a range 
in cooling rate below those of an end-quenched bar 
was developedi23 as part of the program of Project 
NRC-14. 

The cooling rate at 1300 F obtained with the spe- 
cial hardenability bar ranged from about 5 to 1 de- 
gree F per second. The utility of this air-cooled 


hardenability test bar was not so great as originally 
anticipated because, when testing 20 steels of heavy 
armor composition, not one changed by more than 
2 points Rockwell C between the slow- and fast- 
cooled end, and only one steel exhibited a conspicu- 
ous change in microstructure within the length of 
this special hardenability bar. 

In heavy armor sections, the cooling rate on 
quenching at the center of the section is much 
slower than that of the slowest cooling location on 
the standard end-quench hardenability specimens, 
and the amounts of dislocation of the isothermal 
S-curve produced by continuous cooling is unknown 
and unpredictable. An attempt was made to de- 
velop a more rational relationship between trans- 
formation during cooling and transformation at 
constant temperature. The results were intended 
to make possible predictions of the microstructure 
present at the center of heavy armor plate by using 
the isothermal transformation diagram of several 
proposed heavy armor plate analyses and by using 
the cooling data on heavy plate. 

In the investigation, five 0.3 per cent carbon alloy 
steels of various chromium contents were used.^-® 
Cooling was first closely approximated by constant 
cooling. With this treatment, it was found that 
from the Ae 3 temperature down to about 1130 F 
the time spent at a given temperature divided by 
the time required for beginning isothermal trans- 
formation at that temperature may be regarded as a 
fraction of the nucleation period, and that when 
the sum of such fractions is equal to 1, nucleation 
begins. Temperatures from about 1130 F to the Ms 
temperature constitute a distinct range that is not 
additive with the higher range mentioned. These 
findings were used as a basis of a mathematical ex- 
pression which permit calculation of the tempera- 
ture at which transformation begins during cooling. 
In checking the validity of the mathematical ex- 
pression by use of an end-quench bar, for which 
accurate cooling curves were available, it was found 
that the experimental data and calculated data dif- 
fered appreciably for two of the five steels. 

While the discrepancies that occurred between the 
experimental data and the calculated data can not 
be properly explained at present, there was some 
suggestion that stress may play a highly important 
role in beginning transformation. If stress is capable 
of affecting the decomposition of austenite to bain- 
ite, ferrite, or pearlite, the subject becomes of con- 


CONFIDENTIAL 


48 


ARMOR 


siderable practical interest since present-day use of 
isothermal transformation curves and end-quench 
hardenability data do not consider stress as a trans- 
formation variable. The effect of stress and strain 
on the isothermal transformation of austenite, 
therefore, became part of the research program. Un- 
der certain special conditions, stress and/or strain 
was shown to be capable of affecting the decomposi- 
tion of austenite to ferrite, pearlite, or bainite.^^^ 

Because the tests indicated that, at least under 
certain special conditions, stress or strain can mate- 
rially affect the kinetics of the austenite decomposi- 
tion, the question arose as to whether the stresses 
or strains which developed during the quenching of 
commercial parts are sufficient to affect transforma- 
tion. While the data in this study could not shed 
any light on this practical problem, further consid- 
eration was given to the problem in a study of the 
correlation between the hardness and structure pre- 
dicted on the basis of end-quench tests and the hard- 
ness and structure actually obtained in various sized 
rounds and plates. This investigation also was part 
of Project NRC-14. 

fn this work, plates and rounds of three different 
steels 1 to 4 in. in thickness were water quenched, 
after which hardness traverses and metallographic 
examinations of the specimens were made and the 
results compared with those obtained from end- 
quenched hardenability bars taken from the same 
heat. These hardness and metallographic compari- 
sons were in turn compared with the relationship 
between cooling rates in the end-quenched harden- 
ability bar and cooling rates within the various 
plates and rounds previously determined on Project 
NRC-55 mentioned earlier. The results indicate 
that, at the present time, it is not practical to at- 
tempt to predict either the hardness or microstruc- 
ture that will be obtained in rounds and plates on 
the basis of equal cooling rates, fn other words, a 
point on the end-quench hardenability bar having 
a cooling rate very similar to a particular position 
within some plate or round will not necessarily ex- 
hibit either the same hardness or the same micro- 
structure found at the corresponding location in 
the plate or round. Evidently, factors other than 
cooling rate are capable of appreciably affecting the 
transformation characteristics of the steel. One of 
these factors may be stress. 

One of the subjects investigated was the metal- 


lurgy and properties of armor steels cast or rolled 
in sections 4 in. or more. Because the cooling rates 
in these heavy sections are low, even when the part 
is water quenched, the chance for bainite to form 
during the quench becomes greater than in smaller 
sections despite an increase in alloy content to com- 
pensate for the heavier sections. Pearlite formation, 
on the other hand, becomes less likely because gen- 
erally the pearlite and ferrite transformation is 
repressed more by the increased alloy content than 
is the bainite transformation. 

Although martensite is the desired quenched 
structure in armor plate, the bainite transformation 
products found in the higher alloy steels approach 
closely enough to martensite in structure and hard- 
ness to suggest that their properties after tempering 
may be, at least to a certain degree, comparable 
with those of tempered martensite. 

Past experience in this research program and the 
experience of others have resulted in the unfavor- 
able report on the properties of tempered bainite 
structures in 0.3 per cent carbon steels. If it is rec- 
ognized that bainite structures reduce the low-tem- 
perature notched bar toughness of 0.3 per cent 
carbon alloy steels tempered to low hardness and 
that they, therefore, can be presumed to affect dis- 
advantageously the ballistic properties, it then be- 
comes important to establish the degree of tough- 
ness depreciation associated with various percent- 
ages of bainite and with bainite formed at several 
temperatures. This information would lead to some 
idea of the percentages and types of bainite prod- 
ucts that can be tolerated in heavy armor plate 
and hence aid in establishing the necessary alloy 
limitations. Comparison along this line was made 
on four heavy armor-plate compositions, using heat 
treatments that simulate those in commercial opera- 
tions as well as a number of isothermal treatments 
intended to produce various mixed bainite and mar- 
tensite structures. Both room-temperature tensile 
properties and V-notch Charpy values, the latter 
also at sub-zero temperatures, were determined on 
specimens tempered to a hardness of 240 to 260 
Brinell after the specific hardening treatment. 

ft was shown that steels having compositions in- 
tended for use in heavy-sectioned armor plate have 
mostly bainite in the quenched structure when 
cooled at a rate equivalent to that in a 3-in. water- 
quenched plate, but the notched bar toughness of the 


CONFIDENTfAL 


NONMAGNETIC ARMOR PLATE FOR AIRCRAFT 


49 


tempered product remains high even when the cool- 
ing rate approaches that o£ the water-quenched 9-in. 
plate. Small percentages ot pearlite in the micro- 
structure were shown to be highly detrimental. The 
presence of small percentages of ferrite, on the other 
hand, did not appear to be too objectionable, pro- 
vided the balance of the structure did not contain 
pearlite. Bainite structures produced by isothermal 
transformation had lower V-notch Charpy values 
than did structures of martensite tempered to the 
same hardness. The notched bar values of bainitic 
structures are improved, however, in going from high- 
temperature bainite to low-temperature bainite.^^^ 

As mentioned earlier, the attributes of boron to 
increase the hardenability of steel and to achieve 
this increase in hardenability without a concurrent 
increase in quench-crack susceptibility led to a 
study of boron in steels suitable for heavy armor 
with the possibility of obtaining structure appreci- 
ably more martensitic in character. As stated earlier, 
boron added to the hardenability of the steels with- 
out conferring other less desirable characteristics. 

The sum total of all the investigations on heavy 
armor indicates that there is no acceptable short-cut 
to the evaluation of structure and properties at the 
center of very heavy sections and that actual 
quenching of heavy sections, cutting them up, and 
determining the interior structure and mechanical 
properties will, in the long run, be the best way of 
obtaining reliable information. 

2 4 NONMAGNETIC ARMOR PLATE 
FOR AIRCRAFT 

Prior to World War II, it had been considered 
that aircraft armor should be nonmagnetic or mag- 
netically stable so that it would not interfere with 
the functioning of the magnetic compass. Although 
the compensating magnets in the compass could 
correct for the effect of steel in the engine and in 
structural parts, aircraft armor appeared to change 
its polarity continually so that compensation could 
not be satisfactorily accomplished. 

In the Spring of 1941, the Bureau of Ordnance, 
Navy Department, urged NDRC to investigate 
steels of the nonmagnetic type, pointing out that 
if nonmagnetic armor of standard type could not 
be developed, it would be helpful if the magnetic 
stability of aircraft armor could be increased. This 


problem was also of interest to the Army Air Forces 
under control number AC-6. 

Accordingly, the Metallurgy Section of the former 
Division B, NDRC, established Projects B-104 and 
B-208 (AC-6) (NO-B13), Development of Non- 

Magnetic Armor Steel, at the Massachusetts Insti- 
tute of Technology in July 1941. The program in- 
cluded a survey of the requirements as well as the 
materials available for nonmagnetic armor and a 
laboratory investigation of these materials. This in- 
vestigation included studies of steel making meth- 
ods, heat treatment, metallographic studies, and 
tests, such as magnetic tests, hardness tests, tensile 
tests, and ballistic tests. 

The principal phase of the investigation was a 
study of Hadfield’s manganese steel as it was the 
most promising of the nonmagnetic materials avail- 
able. It contains usually 1.0 to 1.4 per cent of car- 
bon and 11 to 14 per cent of manganese and, when 
quenched from above 1800 F, it is nonmagnetic. Its 
properties were varied by changes in composition 
through the use of alloy addition agents, cold work, 
and heat treatment. Forty-three heats of steel of this 
general type were made, forged, and tested.i32. 133 

The hardness, yield strength, and ultimate tensile 
strength in the quenched state are increased by ad- 
ditions of silicon, chromium, molybdenum, tung- 
sten, and vanadium. At the same time, ductility is 
sometimes diminished but never below an elonga- 
tion of 20 per cent in 2 in. Aluminum and nickel 
have a slight softening effect but at the same time 
increase the elongation and tensile strength. 

Cold reduction increases the hardness and tensile 
strength of all specimens tested. Many but not all of 
the steels retained most of their ductility even when 
cold rolled to a hardness of 35 Rockwell C. In most 
cases the steels retained their nonmagnetic character. 

Heat treatment in the form of tempering or ag- 
ing at 500 to 1100 F caused a slight increase in 
hardness and generally a marked decrease in ductil- 
ity. At the same time, many of the steels became 
magnetic. In no case could it be said that the prop- 
erties were improved by heat treatment. 

Several compositions had good physical proper- 
ties and were nonmagnetic in the quenched or cold- 
rolled states, although they were somewhat mag- 
netic after rupture in tension. These and several re- 
lated compositions offered considerable promise as 
nonmagnetic armor and investigations of their bal- 


CONFIDENTIAL 


50 


ARMOR 


listic properties were made at Watertown Arsenal 
and the Naval Proving Ground.i34 

In none of these ballistic tests on specimens of ar- 
mor 3/g in. thick was the ballistic limit as high as 
that of good homogeneous armor plate. It was 
found that penetration resistance was improved by 
cold rolling, giving rise to a slight increase in mag- 
netic permeability in most cases. Tempering at any 
temperature failed to improve and often lowered 
the ballistic properties. 


25 INDEXING OF DIVISION 18 REPORTS 
ON ARMOR 

An index of the Division 18 reports on armor 
was prepared by the Research Information Division 
of the War Metallurgy Committee. This index^^s 
gives a subject list of the various projects with the 
reports issued on each, a brief abstract of each re- 
port, and a subject index of the reports. It is be- 
lieved that this index will enhance the usefulness 
of the many reports on the subject. 


L 


Chapter 3 

GUNS AND GUN STEELS 


INTRODUCTION 

T he division 18 program on guns and gun steels 
embodied nine research investigations. These 
included studies of the steel quality required for 
wrought gun tubes, improvement in gun steel ingot 
practice, the prevention of cracking in gun tubes, 
the heat treatment of gun steels, the control of steel 
making and plant practice in the manufacture of 
seamless gun tubes, and the development of new 
gun steels of improved physical properties. 

The various projects were established as the re- 
sult of suggestions of the Research Group of the 
Subcommittee on Gun Forgings, Ferrous Metallur- 
gical Advisory Board, Army Ordnance Department; 
Watertown Arsenal; and Watervliet Arsenal. These 
organizations cooperated very closely with the War 
Metallurgy Committee in the conduct of the proj- 
ects. The work resulted in an increased output of 
large guns of all sizes and much better testing pro- 
cedures, insuring higher quality in the finished 
guns. In one instance, simplified testing procedures 
based on the NDRC studies reduced the number of 
required tests by 75 per cent, thus making sub- 
stantial savings in time, manpower, and testing 
equipment. It has been estimated that the annual 
savings as a result of this one development might 
have amounted to $1,000,000, a sum more than 
twice the total cost of the entire Division 18 gun steel 
research program. 

The results of these studies were distributed in 
NDRC reports to the Armed Services and to all the 
manufacturers of gun forgings supplying gun tubes 
to Army Ordnance. The latter comprised the mem- 
bership of the Subcommittee on Gun Forgings, 
Ferrous Metallurgical Advisory Board, Army Ord- 
nance Department. 

3 2 STEEL FOR GUN TUBES 

The quality of gun steel is considered good if the 
gun tube behaves satisfactorily when used in the 
manner for which it was designed, and if when 
worn out it endured a normal useful life. 


In the spring of 1941 the following major ques- 
tions arose with respect to gun steel quality: 

1. What minimum steel quality is essential for 
the best performance of gun tubes? 

2. What tests are of the most value for measuring 
this quality? 

3. Does practically all gun steel produced have a 
quality higher than that essential for best perform- 
ance? 

4. Do specifications for gun tubes insure that (a) 
all tubes accepted have adequate quality, and (b) 
all tubes rejected have inadequate quality for good 
performance? 

Answers to these questions were considered im- 
portant because it was believed that from them 
could be determined the kind of research program 
likely to be most valuable to the Armed Services. 
For example, if for forgings the minimum steel 
quality that should be tolerated were known in 
terms of certain properties such as yield strength, 
transverse reduction of area, and transverse impact 
resistance, then a specification could be written 
utilizing this information. Further, if the quality 
produced were practically always higher than the 
minimum required to give best performance, in- 
spection and testing could be reduced to a mini- 
mum. Under these conditions, research to improve 
the steel quality of gun tubes would tend to be 
discouraged. 

When the NDRC program first was started, it 
was believed that (1) the minimum steel quality 
essential for the best performance of gun tubes was 
not known, (2) the best tests for measuring gun 
steel quality were tensile, impact, macroetch, and 
proof tests, (3) more than 90 per cent of all steel 
produced for gun tubes had a quality above the 
minimum specified and above the minimum re- 
quired for good performance, and (4) specifications 
in use in 1941 accepted with considerable certainty 
only tubes of adequate steel quality. 

Most of the gun tube work on NDRC projects 
was planned to secure information to answer the 
questions listed above more quantitatively than had 
previously been possible and to be used in the de- 
velopment of better specifications for the accept- 


51 


52 


GUNS AND GUN STEELS 


ance of gun tubes. Practically all work on steel for 
gun tubes was done on wrought tubes. 

1 Steel Quality of Wrought Gun Tubes 

The steel quality of a heat-treated gun tube forg- 
ing is said to be good when (1) the yield strength falls 
between the specification limits, (2) the transverse 
impact resistance is high, (3) the transverse ductility 
is high, (4) the forging is free from porosity or 
unsoundness, excessive nonmetallic matter, and in- 
ternal and external defects of harmful character. 

Yield strength is probably the most important 
property in gun tubes, and fortunately it is the one 
about which there is practically complete agree- 
ment as to its importance. The magnitude of the 
pressure a tube of given yield strength and of given 
dimensions will resist in service before the bore is 
expanded significantly is quite definitely known. 
Such knowledge is used in the design of gun tubes 
and in the establishment of specification limits for 
yield strength. Minimum yield strength require- 
ments as written into specifications permit liberal 
allowances for normal variations of yield strength 
in a tube, among tempering batches, and among 
heat treatment practices. The choice of a maximum 
yield strength limit is much more arbitrary than is 
the choice of the minimum. Some even believe that 
a maximum yield strength should not be specified 
at all. Sometimes a maximum hardness but no 
maximum yield strength limit is specified. 

It is often stated that gun tube steel should have 
maximum toughness at the yield strength level to 
which the tube is tempered. Maximum toughness 
is obtained by quenching to martensite and subse- 
quent tempering. Therefore, this statement is likely 
to be more correct when referring to tubes which 
will be critically stressed in service and subjected 
to high circumferential elastic strain, such as in a 
radial bore strain of 0.003 in. or more,^^® than 
when referring to ordinary gun tubes. It may be 
that practically all the ordinary gun tubes of large 
wall ratios, 2.0 or above, and worn out by erosion, 
perform just as well whether they have or have not 
maximum toughness providing that the yield 
strength is adequate. Despite this, it is probably well 
worth while to try always to develop the maximum 
toughness at a given yield strength, since tubes with 
maximum toughness when subjected to stresses de- 
veloped by premature explosions are less likely to 


fragment into as many small pieces as tubes with 
inferior toughness. Frequently, however, because of 
size effect it is not possible to develop maximum 
toughness by quenching completely to martensite 
and drawing to the required yield strength. 

The uncertainty concerning the toughness is re- 
quired in the average gun tube, for best perform- 
ance has led to much controversial discussion 
regarding the choice of minimum transverse reduc- 
tion of area and minimum transverse impact values 
to be written into specifications. Opinions have 
varied from the one extreme that no minimum 
transverse reduction of area and no minimum trans- 
verse impact resistance values should be specified 
for the acceptance of the garden variety of gun 
tubes, to the other extreme that minimum trans- 
verse reduction of area and minimum transverse 
impact requirements should be as high as possible, 
providing they do not cause a serious loss in pro- 
duction. As a result of the work done at Watertown 
Arsenal and by NDRC, more is known now about 
the relation between transverse impact resistance 
and performance and the relation between trans- 
verse reduction of area and performance than was 
known at the beginning of World War II. 

Watertown Arsenal has reported that many tubes 
of recent design which are critically stressed in ser- 
vice develop progressive damage to the extent that 
they must be taken out of service before they are 
worn out by erosion. If this were not done it is be- 
lieved such tubes would finally burst. Obviously it 
is much more serious to have tubes fail because of 
progressive stress damage than because of erosion. 
More recent results from Watertown Arsenal have 
indicated that the higher the impact resistance at 
a given yield strength, the better the tube will resist 
progressive stress damage. It was decided on the 
basis of Watertown Arsenal’s findings on progres- 
sive stress damage that every effort should be made 
to determine what factors cause progressive stress 
damage and how this damage can be avoided. Work 
on this problem was started under NDRC and con- 
tinued under an Army Ordnance contract super- 
vised by Watertown Arsenal. Watertown Arsenal 
recommended that specifications used for the ac- 
ceptance of those gun tubes likely to suffer seriously 
from progressive stress damage should include an 
impact requirement, and this recommendation was 
accepted by Army Ordnance. Statistical studies 
were made under Project NRC-38 (OD-34-3), Im- 


CONFIDENTIAL 


STEEL FOR GUN TUBES 


53 


provement in Wrought Gun Tubes, conducted by 
Carnegie Institute of Technology. These studies 
yielded the highest transverse impact values at vari- 
ous yield strength levels which could be specified 
without causing any serious loss of production. 
These values were accepted tentatively by Army 
Ordnance and were written into U. S. Army Speci- 
fication 57- 106 A after minor changes had been 
made by Watertown Arsenal. 

Since the establishment by the Metallurgy Sec- 
tion of the former Division B, NDRC, of the initial 
investigation, Project B-90 and B-160 (OD-34-3), 
Steel for Gun Tubes, it has been the opinion of the 
investigators at Carnegie Institute of Technology 
that, down to well below an average transverse re- 
duction of area of 20 per cent, the effect of trans- 
verse ductility in gun tubes on their performance 
is practically insignificant, providing the tubes in 
service fail by erosion. Jn one investigation an 
attempt was made to determine whether or not the 
performance of four 37-mm M6 tubes with trans- 
verse reduction of area which averaged between 19 
and 26 per cent was inferior to the performance of 
two similar tubes with averages of 43.8 and 39.6 per 
cent, respectively. The 19 to 26 per cent averages 
represent material of the lowest reduction of area 
in the transverse direction [RAT] values likely to 
be accepted under specification 57-105-1, whereas 
the 43.8 and 39.6 per cent averages represent mate- 
rial of high RAT quality. In this study a frequency 
curve was determined for each tube which indi- 
cated roughly the magnitude of the variation of 
RAT per tube and the average RAT for each tube. 
No significant difference could be found between 
the performance of the two 37-mm M6 gun tubes 
with high transverse ductility (average RAT, 40 
per cent) and the performance of the four 37-mm 
M6 tubes with low transverse ductility (average 
RAT, 20 per cent). The tube with the lowest RAT 
quality (average RAT, 19.8 per cent) had the 
longest life. The results suggested that some vari- 
able or variables other than RAT had a much more 
significant influence on gun life and that the rela- 
tion between RAT and performance was relatively 
of minor importance. All six tubes failed because of 
excessive erosion and scoring and not because of 
progressive stress damage. It was tentatively con- 
cluded that transverse ductility down to 20 per cent 
average RAT does not control the length of useful 
life or the performance of tubes which fail by ero- 


sion. It was pointed out, however, that it is not 
known whether transverse reduction of area is an 
important variable in those gun tubes whose useful 
life is controlled by progressive stress damage rather 
than by erosion.^ The 75-mm M6 and 76-mm M1A2 
tubes are in this class.^^s Probably RAT does tend 
to influence the behavior of tubes with respect to 
progressive stress damage, since a deficiency of im- 
pact resistance aids the development of such dam- 
age and a positive correlation has been found to 
exist between impact resistance and transverse re- 
duction of area among tubes from different heats. 
Of the several hundred tubes used in the determina- 
tion of the correlation, those from low average RAT 
heats usually gave low transverse impact averages 
and those from high average RAT heats usually 
gave high transverse impact averages. All tubes 
were severely quenched before being tempered and 
there was no reason to suspect that temper brittle- 
ness or an inadequate quench was responsible for 
the low impact values observed. The yield strength 
level selected for the study was 150,000 psi. 

3.2.2 Significance of Tests Used in 
Determination of Gun Tube Quality 

Most tubes which are worn out fail because of 
erosion. Some are taken out of service because the 
probability of the development of serious progres- 
sive damage in tubes continued in service for a 
longer period is considered too high. Practically 
none fail because of a deficiency of yield strength 
or because of extraneous metallurgical defects, such 
as cracks, voids, or bore defects. Apparently, the 
tensile test used to insure adequate yield strength 
and the macroetch and visual tests used to insure 
freedom from damaging defects in accepted tubes 
have been extremely effective in achieving the ob- 
jectives sought. 

It is believed that gun tube steel quality bears no 
significant relation to erosion. Much more impor- 
tant factors which control erosion are the character 
of the projectile and the conditions of use. 

Since tubes of maximum toughness at a given 

a Due consideration must be given to the limitations imposed 
by this small number of firing tests. Rigid general conclusions 
from these tests alone are not possible in view of the effect of 
type of failure and the relation thereto of specific designs and 
character of service. Specifications cannot be influenced until 
more data are available. 


GONFIDENTIAL 


54 


GUNS AND GUN STEELS 


yield strength resist progressive stress damage better 
than do others, a Charpy impact requirement is in- 
cluded in U. S. Army Specification 57-106A to in- 
sure that all tubes subjected to conditions which 
normally cause serious progressive stress damage 
shall have more toughness than the specified 
minimum. 

Under Project NRC-38 (OD-34-3) carried out at 
Carnegie Institute of Technology, a study was made 
of the significance of the various tests used in de- 
termining the quality of gun tubes. Statistical stud- 
ies were made also to determine the minimum 
requirements for yield strength, transverse impact, 
and transverse reduction of area. 

Transverse Tensile Test for 
Wrought Gun Tubes 

In this test yield strength, tensile strength, trans- 
verse elongation, and transverse reduction of area 
values are determined. Of these, the yield strength 
value is important for reasons already mentioned, 
but the tensile strength value is relatively unimpor- 
tant. To what extent transverse elongation and 
transverse reduction, values are of value is open to 
considerable question, primarily because too little 
is known about the relations between transverse 
elongation and gun tube performance, or between 
transverse reduction of area and gun tube 
performance. 

It is quite certain that a minimum yield strength 
requirement should always be specified for the ac- 
ceptance of gun tubes. It is not at all certain, how- 
ever, that a minimum transverse elongation or a 
minimum transverse reduction of area should be 
specified. Nevertheless, with present knowledge such 
minima in specifications are the best known assur- 
ance of adequate quality. Probably much more 
transverse ductility is needed in tubes to be auto- 
frettaged than in others. 

Transverse Charpy Impact Test for 
Wrought Gun Tubes 

It already has been pointed out that by use of 
this test in U. S. Army Specification 57-1 06A assur- 
ance is given that tubes which usually suffer se- 
verely from progressive stress damage practically 
always have a certain minimum toughness. For this 
reason the impact test is considered important. The 
present level of this minimum is sufficiently low to 
allow acceptance of almost all tubes of the types 
referred to above. The extent to which the impact 


test requirements causes an increase of average 
toughness or an increase of minimum toughness in 
accepted gun tubes is not known, so that a quanti- 
tative evaluation of the usefulness of the test cannot 
be given, although it is probable that significant 
benefits have been obtained directly or indirectly by 
specifying an impact test. The direct beneficial effect 
results from the rejection of a few tubes of very 
low impact resistance, and the indirect beneficial 
effect, which is probably much more important, 
results from the extra efforts made by producers to 
insure that the average impact resistance quality 
shall be so high that no tubes are likely to fail because 
of deficiency in impact resistance when presented for 
inspection. Improved impact quality may result from 
the use of a steel of higher alloy content, a more 
severe quench before the temper, and an improved 
tempering procedure to avoid temper brittleness. 

The significance of this test has been thoroughly 
discussed in Watertown Arsenal reports and in 
publications by the Arsenal’s personnel. 

Macroetch Test 

The macroetch test has been used with consider- 
able success for locating extraneous defects in gun 
tubes, such as all kinds of cracks, fiakes, porosity or 
unsoundness, excessive nonmetallic matter, and 
bore defects. 

Often when disks are etched, especially when 
they come from large tubes, the acid attacks some 
regions faster than others with the result that the 
etched surfaces to be examined show numerous 
deep holes which are usually round. Such holes in 
macroetched disks from 8-in. howitzer forgings have 
been observed to be as large as i/4 in. deep and I/3 
in. in diameter. It is imperative that these holes and 
the apparent porosity caused by the etchant not be 
confused with the voids and true porosity which 
obviously may be present in a tube before etching. 
At the beginning of World War II, the quality of 
macroetched disks having this appearance was con- 
sidered inferior by many inspectors and for a time 
they rejected tubes from which such disks were cut. 

Several tensile specimens were cut from disks 
such as those referred to above, and RAT values 
were determined. The results showed very definitely 
that transverse reduction of area is on the average 
quite as high for specimens taken from those re- 
gions most rapidly dissolved by acid as for speci- 
mens taken from regions least rapidly dissolved by 
acid. Additional studies indicated that the average 


CONFIDENTIAL 


STEEL FOR GUN TUBES 


55 


RAT value for specimens from a macroetched disk 
containing a considerable number of etched-out 
holes is about as high as the average RAT value 
for specimens from a comparable macroetched disk 
relatively free from the etched-out holes. When in- 
spectors became aware of these results, tubes were 
not rejected simply because macroetched disks from 
them showed round holes or pits such as those de- 
scribed above. 

Other work indicated that the quality o^ forgings 
with respect to transverse ductility cannot be 
judged from the dendritic pattern observed among 
macroetched disks, at least for the range of pattern 
variation studied at Carnegie Institute of Technol- 
ogy under Project NRC-38. It was shown that the 
macroetch test has but a limited usefulness in show- 
ing the depths to which forging has penetrated and 
destroyed the pattern. 

Proof-Firing Test 

The proof-firing test is essentially a performance 
test in which at least one round is fired at about 
115 per cent of normal pressure. The bore of any 
tube deficient in yield strength will expand when 
proof fired. One advantage of the proof-firing test 
over the others referred to earlier is that the entire 
tube is involved. 

There is considerable assurance that tubes of 
types which normally do not suffer seriously from 
progressive stress damage and which meet proof- 
firing test requirements will behave satisfactorily in 
the field and will not fail because of inferior steel 
quality. However, the proof-firing test does not in- 
sure that a tube subjected to conditions responsible 
for serious progressive stress damage will not fail 
within its normally expected useful life. One tube 
with low impact resistance which met proof require- 
ments failed because of progressive stress damage 
after about three rounds, while a similar tube 
which also met proof requirements failed by pro- 
gressive stress damage after 1,800 rounds. This tube 
also had a low impact resistance. Since the proof- 
firing test does not necessarily insure that those tubes 
of certain designs, that is, the 75-mm M5, which meet 
the test requirements will not fail by progressive 
stress damage within their normally expected lives, 
it is imperative that such tubes have considerable 
toughness or high impact resistance. Tubes with 
high toughness resist progressive stress damage bet- 
ter than do tubes of low toughness. 


3.2.3 Primary Objective Sought as a Result 
of Statistical Studies 

One of the major objectives of the work done 
under Project B-90 and B-160, Steel for Gun Tubes, 
and Project NRC-38, Improvement in Wrought 
Gun Tubes, was to supply information based on a 
statistical analysis of transverse tensile and trans- 
verse impact test data so that a specification could 
be written which would give an extremely high de- 
gree of assurance that the steel quality of accepted 
wrought gun tubes*’ with respect to yield strength, 
transverse impact, and transverse reduction of area 
would be above the minimum needed for good per- 
formance, and that only an extremely small number 
of tubes having more than the minimum required 
would be rejected. In addition, it was desired that 
new specifications for gun tubes should require less 
inspection and testing than formerly. 

To attain the objectives sought every effort was 
made to determine (1) the quality needed, (2) the 
quality produced, and (3) the minimum require- 
ments for yield strength, transverse impact, and 
transverse reduction of area which should be speci- 
fied in order to guarantee with better than a 99 
per cent certainty that no tubes with less than the 
minimum needed for good performance would be 
accepted. As a result of these efforts, specifications 
for gun tubes written by Army Ordnance and in 
use at the end of World War II were far superior 
to those in use at its beginning. 

Minimum Quality Needed and 
Specification Requirements 

The fundamental weakness of most specifications, 
including those for gun tubes, is that generally 
they are based on what quality is produced or can 
be produced, rather than on what quality is needed. 
Unfortunately, information relating to the required 
quality is generally so scanty as to make it impos- 
sible to write a specification which will accept all 
material of a quality above the minimum needed 
and will reject all other material. 

From results obtained under NDRC Project NRC- 
38 (OD-34-3) and from results supplied by Water- 

b Wrought gun tubes consist of (1) seamless tubes, and (2) 
forgings. Work on centrifugal castings similar to that referred 
to above is now being done at Carnegie Institute of Tech- 
nology under a direct contract with the Army Ordnance 
Department. 


CONFIDENTIAL 


56 


GUNS AND GUN STEELS 


town Arsenal’ the following conclusions can be drawn. 

1. The minimum reejuired yield strength needed 
is relatively well known. The minimum given in 
specifications was determined from available infor- 
mation about (a) the minimum needed and (b) the 
variation of yield strength normally present in tubes 
submitted for inspection. 

2. The highest possible value of transverse impact 
resistance is necessary, at least for tubes likely to 
suffer seriously from progressive stress damage. The 
minimum needed for other tubes which normally 
fail by erosion is not well known; it is frequently 
accepted as being so low that no minimum need 
be specified. The minimum transverse impact re- 
quirement specified in U. S. Army Specification 57- 
106A for acceptance of tubes likely to suffer seri- 
ously from progressive stress damage was deter- 
mined more by production impact resistance quality 
than by what impact resistance was thought to be 
needed for the best performance of gun tubes. If 
the production quality had been higher than it was 
in World War II, then the minimum transverse im- 
pact requirement specified in 57-1 06A would prob- 
ably have been higher also. 

3. The minimum transverse reduction of area 
needed is not known. It appears probable from work 
done^^'* that the RAT quality produced is practi- 
cally always above the minimum needed for the 
good performance of gun tubes and above the mini- 
mum specified. 

On the basis of information presented in the 
above summary, it is believed that specifications for 
yield strength as set by Army Ordnance in U. S. 
Army Specification 57-106A and in appropriate 
drawings are about as they should be. Specification 
requirements for RAT, which are now so low that 
they are unlikely to cause more than an insignificant 
number of rejections, should remain unchanged, at 
least until RAT needs are much better known and 
more clearly defined than at present. Specified min- 
imum transverse impact requirements for tubes 
likely to suffer severely from progressive stress dam- 
age should be raised whenever that can be done 
without interfering seriously with production. 

3.2.5 Relation Between NDRC 

Investigations and Development of 
Army Ordnance Specifications 

After the minimum specifications were deter- 
mined with respect to yield strength, transverse re- 


duction of area, and transverse impact, the next 
problem was to write specifications insuring that 
only tubes of adequate yield strength, transverse re- 
duction of area, and transverse impact resistance be 
accepted. It was necessary to make a thorough sta- 
tistical analysis of gun tube tensile and impact data 
in order to obtain the information required for the 
best solution of the problem. This analysis was 
started under NDRC Project NRC-38, Improve- 
ments in Wrought Gun Tubes, at Carnegie Insti- 
tute of Technology and is continuing under a di- 
rect contract with Army Ordnance. Obviously, a 
complete statistical analysis of all existing tensile 
and impact World War II data is very time con- 
suming, involving the use of approximately one 
million data. Fortunately, extremely valuable re- 
sults were obtained on the basis of a study of about 
one-fifth of the total data available. 

Before Army Ordnance could write a new speci- 
fication which would allow production of gun tubes 
to operate as efficiently as possible and at the same 
time would guarantee that only tubes having more 
yield strength, transverse reduction of area, and 
transverse impact than the minimum would be ac- 
cepted, it was necessary to know what quality of 
product with respect to the properties indicated was 
being submitted for inspection. 

Under Project B-90 and B-160, Steel for Gun 
Tubes, and Project NRC-38, Improvement in 
Wrought Gun Tubes, investigations were carried 
out at Carnegie Institute of Technology to deter- 
mine the following: 

1. Average transverse reduction of area quality. 

2. Transverse reduction of area variation. 

3. Degree of control of transverse reduction of 
area. 

4. Average yield strength quality. 

5. Yield strength variation. 

6. Degree of control of yield strength. 

7. Average transverse impact quality. 

8. Transverse impact variation. 

9. Degree of control of transverse impact. 

10. Relation between yield strength and trans- 
verse reduction of area. 

11. Effect of reheat treatment (requench and 
draw) and redraw on transverse reduction of 
area. 

12. Relation between yield strength and trans- 
verse impact. 

13. Effect of forging reduction on transverse re- 
duction of area. 


CONFIDENTIAL 


STEEL FOR GUN TUBES 


57 


14. Effect of angle of test, relative to fiber direc- 
tion, on transverse reduction of area and on 
transverse impact resistance. 

Average Transverse Reduction of Area Quality 

Statistical studies to determine average RAT 
quality of tubes presented for inspection were made 
first using RAT data for seamless tubes. There were 
several reasons for this procedure. Seamless tubes 
were not used in any war before W^orld War fl. 
Furthermore, the specihcation written for the ac- 
ceptance of such tubes was considered imperfect 
and was for temporary use only until a better specih- 
cation could be developed. Seamless tubes were 
made from high RAT heats and were quenched and 
heat treated using practices which, with modern 
metallurgical knowledge, should give an excellent 
uniformity of product. Furthermore, early in World 
War If, seamless tubes were being produced at a 
rate of about 6,000 per month (4,000 40-mm Ml 
and 2,000 75-mm M3). Since heat lots consisted of a 
very large number of tubes, usually more than 250 
40’s and 100 75’s per heat, the probability that the 
war effort would beneht quickly and signihcantly 
from results of statistical studies seemed high. 

The average RAT quality of seamless tubes was 
found to be about 50 per cent for 40-mm tubes, 41 
per cent for 75-mm M3 tubes, and 48 per cent for a 
few 75-mm howitzers. Average yield strengths were 
approximately 110,000 psi for 40-mm Ml tubes, 

115.000 psi for 75-mm M3 tubes and 110,000 psi for 
the 75-mm howitzers. The lowest and highest heat 
RAT averagesc were found to be 42.5 per cent and 

56.0 per cent for 40’s, 34.8 per cent and 48.0 per 
cent for the 75’s and 47.7 per cent and 48.4 per cent 
for the howitizers. Heat RAT averages were deter- 
mined for about 150 40-mm heats, 250 75-mm M3 
heats and 3 75-mm howitzers heats. The averages 
determined for tubes were found to be usually about 
the same as their respective heat averages. The max- 
imum difference, based on a large number of values, 
between a tube RAT average and the heat RAT 
average generally was found to be less than 3 per 
cent, although there was some indication that the 
maximum difference between a tube and heat aver- 
age might be occasionally 5 per cent or 6 per cent 

cAll RAT values for heat-treated seamless tubes from a given 
heat are averaged and this is called the heat RAT average. 
Actually the true heat averages for 40-mm heats may be slightly 
lower than given, because specimens for tensile tests of 40-mm 
tid)es were cut from the upset breech ends. Values for upset 
ends are on the average about 3 per cent higher than for other 
parts of the tubes. 


higher. By requiring that the minimum average 
quality of 40-mm Ml and 75-mm M3 tubes accepted 
as heat lots shall be at least 6 per cent higher than 
the minimum average quality of tubes accepted as 
individual tubes (by the prescribed method of sam- 
pling and testing), it is more than 99.9 per cent cer- 
tain that the minimum average RAT quality of any 
tube accepted in a heat lot is not less than the min- 
imum average RAT quality of any tube accepted 
on an individual rather than on a heat lot basis. 
This conclusion was reached because all statistical 
evidence supported the belief that this higher min- 
imum average quality required of tubes accepted in 
heat lots is sufficient to insure that differences be- 
tween tube RAT average and the heat RAT aver- 
age, and differences between the maximum varia- 
tion of RAT in a tube and the maximum variation 
of RAT among all the tubes of the heat, are small 
enough so that the minimum RAT quality of ac- 
cepted tubes is not lowered. 

Statistical studies of RAT values for forgings 
were much less complete than were those for seam- 
less tubes. Data for forgings from all companies of 
all sizes, 37' mm to 16 in., give heat RAT averages 
which fall between limits of about -30 per cent and 
55 per cent at a yield strength level of about 

110,000 psi, between 30 and 50 per cent at a level 
of 130,000 psi, between 25 and 40 per cent at a level 
of 150,000 psi, and between 20 and 38 per cent at 
a level of 165,000 psi. 

Transverse Reduction of Area Variation 

The observation that RAT at a given yield 
strength varies considerably in all gun tubes and 
the realization of the importance of this fact in its 
relation to specifications was probably the most im- 
portant single result of the statistical work done on 
gun tubes under NDRC. It changed completely the 
fundamental approach to the problem of writing 
gun tube specifications. Specifications were subse- 
quently written by the Army Ordnance Department 
substituting a statistical approach for the one pre- 
viously used, and the benefits derived by both the 
Army Ordnance Department and producers of gun 
tubes were considerable. 

Statistical studies of RAT values for specimens 
from seamless tubes of 40-mm Ml and 75-mm M3 
sizes indicated that the maximum variation of RAT 
usually is about the same in a small section of a gun 
tube as (1) in the whole gun tube, (2) among all 
the gun tubes from one ingot, and (3) among all 


CONFIDENTIAL 


58 


GUNS AND GUN STEELS 


the gun tubes from a heat. In poor quality heats the 
maximum RAT variation among the tubes is us- 
ually higher than among tubes from good heats. 
The maximum variation observed was rarely less 
than 20 per cent from a minimum of 35 per cent 
RAT to a minimum of 55 per cent RAT at a yield 
strength of 120,000 psi. It was obvious from these 
results that to establish RAT quality precisely a 
large number of RAT values are required. A single 
value has practically no meaning except as it relates 
to other values. Fortunately, since tubes from a 
given heat are usually about alike, and since a large 
number of tubes, usually from 100 to 300 or more, 
are generally made from the same heat, a tensile 
test per tube is not necessary for the determination 
of the RAT quality of the heat, and within the de- 
sired accuracy, the RAT quality of any tube in the 
heat. Obviously, for the determination of RAT 
quality in a large unit, the larger the number of 
small units (tubes) making up the large unit (heat 
or practice), the smaller the number of RAT values 
per small unit required. Generally more than 100 
seamless 75-mm M3 and 200 seamless 40-mm Ml 
tubes were made per heat and many fewer tests 
than one per tube were necessary to evaluate the 
RAT quality of a heat. 

From the above discussion and from other facts 
previously stated in this summary, it is much more 
desirable to consider the heat unit, or even a large 
unit, rather than the individual tube unit as the 
logical unit to use in specifications of RAT quality 
for wrought gun tubes. This is especially true when 
the product presented is consistently excessively 
good or excessively bad. The use of the heat lot 
unit in Specification WVXS-78, developed by the 
Army Ordnance Department on a basis of this 
NDRC investigation, resulted in the saving of 
about 100,000 tensile tests in one year during 
World War II. Other savings of tests, not yet esti- 
mated but known to be quite considerable, have 
resulted from the use of the heat unit concept in 
other specifications developed later in these studies, 
namely, WVXS-88, WVXS-95, and U. S. Army Speci- 
fication 57- 106 A used for the acceptance of gun 
tube forgings. Of course, when the heat is of border- 
line RAT quality, the use of the individual tube 
unit in specifications may be justified since, as al- 
ready pointed out, the average RAT value of the 
worst tube in a heat may occasionally be 6 per cent 
or more lower than the average RAT value of the 
best tube in the same heat. 


In general, studies of RAT data for gun tube 
forgings of sizes from 37 mm to 16 in. confirmed 
the above conclusions. 

Degree of Control of Transverse 
Reduction of Area 

When RAT determinations are made on speci- 
mens from breech and muzzle ends and a tube is 
accepted or rejected on a basis of these RAT values, 
it is at least tacitly assumed that the RAT quality 
of the whole tube is indicated by the RAT quality 
of muzzle and breech ends. When a whole heat of 
tubes is accepted or rejected on a basis of RAT 
values for specimens from the breech (or muzzle) 
ends of some, but not all, of the tubes, then the 
assumption has been made that the RAT quality 
of the whole heat is indicated by the RAT quality 
of the breeches (or muzzles) of the tubes tested. 
The extent to which these assumptions are justified 
is determined by the degree of RAT control result- 
ing from a given practice. Fortunately, so far as is 
known, these assumptions have never been suffi- 
ciently in error to have allowed, either at the prov- 
ing grounds or in the field, the failure of accepted 
gun tubes owing to RAT deficiency. 

Statistical studies were made to determine as 
quantitatively as possible the degree of control of 
RAT achieved in the various practices used by pro- 
ducers of gun tubes in World War II. Plotted con- 
trol chartsi^^’i^i reveal that the degree of control 
of RAT in tubes, among tubes in a heat, and 
among heats in a practice is usually sufficient to 
justify the use of the known laws of chance for the 
determination of RAT quality in gun tubes. By 
use of these laws of probability to determine RAT 
quality, advantages of considerable practical im- 
portance were gained by both the Army Ordnance 
Department and the gun tube producers. Thou- 
sands of RAT data were used for the plotting of 
the control charts, but despite the overwhelming 
evidence of the validity of the conclusions drawn, 
the consequences of its acceptance are still viewed 
with scepticism by many inspectors. Often tubes 
have been accepted from unusually low average 
RAT heats because the one (for small tubes), two 
(for intermediate-sized tubes), or four (for large 
tubes) RAT values were by chance above the mini- 
mum specified. The weakness of such a procedure 
can be amply demonstrated by examining the re- 
sults obtained from the statistical analyses. Before 
long it is probable that specifications will be based 


CONFIDENTIAL 


STEEL FOR GUN TUBES 


59 


on statistical knowledge with respect to the more 
efficient selection of good and rejection of poor qual- 
ity, and with respect to the reduction of the number 
of tests per tube required for the determination of 
RAT quality within a required accuracy. 

Average Yield Strength Quality 

Yield strength values, maximum and minimum, 
are usually chosen by designers of gun tubes. They 
vary, of course, with the size and type of tube and 
with the purpose for which the tube is to be used. 
Therefore, the average yield strength quality must 
be considered in relation to the values chosen by 
the designers. For example, if the maximum and 
minimum yield strength values specified should be 
115,000 psi and 95,000 psi, respectively, and the 
product inspected should have an average yield 
strength quality of 105,000 psi, then the average 
yield strength quality would be considered good. 
The probability of accepting tubes with untested 
regions above or below the specified limits would 
be at a minimum. 

Statistical studies of yield strength data for prac- 
tically all sizes and types of gun tubes revealed that 
initially some producers of gun tubes had difficulty 
in meeting yield strength requirements after the 
first quench and temper.d This was because the 
maximum range of yield strength in certain prac- 
tices was too large to permit observed individual 
yield strength values to fall always between pre- 
scribed limits, and because the average value of the 
yield strength was too close to the minimum yield 
strength specified for all the observed individual 
values to fall above that minimum. Obviously, the 
producer could easily have tempered his quenched 
tubes at a temperature a little lower than the one 
used, to raise his practice average. However, he did 
not do this in the early months of World War II 
because he was faced with another problem whose 
solution also depended on heat treatment; the speci- 
fication of RAT quality, which is higher for low- 
than for high-yield strength tubes. RAT values for 
the acceptance of gun tubes had to be above a cer- 
tain minimum which was the same over the whole 
range of yield strength between the maximum and 
minimum limits specified. Studies were carried out 
to determine the relation between RAT and yield 
strength, 1^2 ^nd subsequently the specification for 

d A tube with too high a yield strength was retempered 
while a tube with too low a yield strength was requenched 
and tempered. 


wrought gun tubes was modified to take this rela- 
tion into account. As a result, producers in general 
raised their practice average, and this brought 
about a drastic reduction in the frequency of occur- 
rence of yield strength values below the minimum 
specified, and greater assurance that no tube ac- 
cepted by Army Ordnance would be deficient in 
yield strength. 

Yield Strength Variation 

As far as is now known, the variation of yield 
strength in gun tubes, which normally fail by ero- 
sion, has no significant effect on their performance, 
provided of course that the tube is not actually de- 
ficient in yield strength. However, a tube with a 
yield strength above the minimum specified and 
with a very large variation may be so hard in some 
parts of the tube as to cause trouble in machining. 
The more uniform the product, the easier it is to 
standardize machining operations. 

As already pointed out, toughness should be as 
high as possible in those tubes which, if worn out 
in service, would fail by progressive stress damage. 
Since impact resistance or toughness is decreased 
usually at a rate of 2 ft-lb or more for each increase 
of 5,000 psi in yield strength, it is important that 
the maximum yield strength be as low as possible. 
Ideally perfect tubes would have the minimum 
yield strength necessary for best performance and 
would be perfectly uniform. In actual practice, the 
need for a small variation of yield strength for 
tubes most likely to suffer from serious progressive 
stress damage must be balanced against what is 
being or can be produced in industry with sufficient 
speed and in sufficient quantity to meet production 
schedules. 

The variation of yield strength in 40-mm Ml and 
75-mm M3 seamless tubes and forgings is rarely less 
than 2,000 psi, is usually about 4,000 psi, and may 
be occasionally as high as 10,000 psi. A producer of 
seamless tubes and a producer of forgings, both us- 
ing electrically controlled heating for tempering, 
produced a more uniform product than did any 
other producers of gun tubes whose products were 
studied. The seamless tubes were tempered in a con- 
tinuous furnace, and one tube followed another of 
the same heat until all the tubes from that heat had 
been started through the furnace. Tubes of another 
heat were then similarly tempered. The forgings 
mentioned above were suspended in the tempering 
furnace in such a way as to afford as uniform heat- 


CONFIDENTIAL 


60 


GUNS AND GUN STEELS 


ing of all the tubes in the batch as possible. Studies 
of the variation of yield strength in heavy tubes 
from good practices are not complete. However, they 
do show that the maximum variation is on the aver- 
age more pronounced in large than in small tubes. 

In poor practices the variation of yield strength 
in gun tubes was found to be rarely below 2,000 
psi, usually about 10,000 psi, and occasionally as 
high as 30,000 psi. Variations of these magnitudes 
have been observed in 37-mm tubes. 

The maximum variation of yield strength among 
tubes in a heat lot® or in a batch was found to be on 
the average about 10,000 psi in a good practice. 
Occasionally a variation as high as 20,000 was ob- 
served. In poor practices the maximum variation 
per batch was on the average about 30,000 psi and 
occasionally a variation as high as 50,000 psi was 
observed. It was found that the maximum variation 
of yield strength in batches containing tubes from 
several heats was on the average much higher than 
in batches containing tubes from only one heat. 
When this information became available, at least 
one producer immediately changed his practice of 
using mixed-heat batches to that of using only one 
heat per batch, with the result that the maximum 
variation per batch dropped on the average to about 
one-half of what it had been before. 

Degree of Control of Yield Strength 

Control-chart studies^^^ indicated that for each 
of about half the practices considered the variation 
of yield strength in one heat lot was about the same 
as in another from the same practice, and the varia- 
tion of yield strength in one batch was the same as 
in another from the same practice. A few exceptions 
to this general conclusion were noted. Variations 
were observed among the heat lot or batch averages 
in each of the practices. These were usually of rela- 
tively small practical importance. As long as the 
quality of control observed in each of the above 
practices remains unchanged, the yield strength 
quality of a tube from any one of the practices may 
be predicted, both with respect to the average for 
the tube and its variation, within an accuracy of 
5,000 psi. Such a prediction probably would be cor- 
rect within the amount mentioned more than 99 
times out of every 100. 

eAs long as one tube immediately follows another from the 
same heat through a continuous tempering furnace, all the 
tubes from that heat considered together comprise a heat unit 
or heat lot. 


Practices of other producers were in much poorer 
statistical control than those just mentioned. As a 
result, more information is required per tube or per 
batch to indicate within a given accuracy what the 
yield strength quality of a tube or batch from these 
producers is likely to be. 

In considering the overall picture of variation 
of yield strength among tubes, it was observed that 
the maximum variation in seamless tubes was 
29,000 psi for 40-mm Ml tubes, and 27,000 psi for 
75-mm M3 tubes. The maximum variation observed 
among 3-in. forgings was 18,000 psi. In each of the 
remaining practices, a maximum variation of more 
than 50,000 psi was observed, indicating poor 
control. 

Average Transverse Impact Quality 

As previously indicated, transverse impact quality 
should be as high as possible in those tubes which, 
if worn out in service, would fail by progressive 
stress damage. For this reason the Army Ordnance 
Department decided to specify an impact require- 
ment for the acceptance of such tubes and needed 
to know what values should be written into the 
specification to insure the best compromise between 
quality accepted and production losses. A correct 
choice of such values depends on a knowledge of 
how critical is the need of transverse impact quality 
at various levels for good performance, and what 
quality is being produced by industry. Under Proj- 
ect NRC-38, a study was made of quality of mate- 
rial being produced with respect to average impact, 
variation of impact, and control of impact. 

Average transverse impact quality varies with 
yield strength. Therefore, transverse impact aver- 
ages or single values have meaning only as they re- 
late to yield strength. An increase of yield strength 
of 5,000 psi usually causes a decrease of 2 ft-lb or 
more in transverse impact resistance. 

With few exceptions, the average transverse im- 
pact quality of any one tube in a heat lot or batch 
was essentially the same as that in any other tube 
from the same heat lot or batch. Differences of con- 
siderable magnitude were observed among averages 
of heat lot and among averages of batches. At a 
yield strength level of about 165,000 psi, the differ- 
ence was 8 ft-lb among heat lots of seamless tubes 
(17 minimum, 25 maximum), 9 ft-lb among batches 
of forgings from one producer (17 minimum, 26 
maximum), and 7 ft-lb among batches of forgings 


CONFIDFNTIAI. 


STEEL FOR GUN TUBES 


61 


from another producer (19) minimum, 26 maxi- 
mum). On rare occasions the differences are larger 
than indicated. Occasionally some tubes in a batch 
are, while others are not, quenched drastically 
enough to give high impact values in the tempered 
material, and this causes large differences of average 
transverse impact quality among the tubes. 

Differences among practice transverse impact 
averages were usually small. In the case of two pro- 
ducers, each making 76-mm tubes, the practice aver- 
ages were 26 ft-lb and 29 ft-lb, respectively. The 
yield strength level was about 150,000 psi. Among 
three producers making 75-mm M5 or M6 tubes, 
the practice averages were 22 ft-lb for each of two 
of the practices, and 24 ft-lb for the third with a 
yield strength of about 165,000 psi. Obviously, at a 
lower yield strength level, the practice average trans- 
verse impact quality is higher. One practice average 
of 45 ft-lb was observed when the yield strength 
level was about 115,000 psi. This was for 155-mm 
mortars. 

Transverse Impact Variation 

Statistical analyses of a large number of data from 
each of several tubes and a large number of data 
from various commercial practices indicate that the 
maximum variation of transverse impact in a gun 
tube is usually about (1) 10 ft-lb at each yield 
strength level in the range between 95,000 and 

150.000 psi, (2) 8 ft-lb between 150,000 psi and 

170.000 psi, and (3) 6 ft-lb between 170,000 psi and 

185.000 psi. Occasionally, one part of a tube may be 
quenched so much more effectively than another 
part of the same tube as to cause a much larger 
variation of transverse impact resistance in the tem- 
pered tube than would be expected normally. Val- 
ues as low as 4 ft-lb and as high as 25 ft-lb have 
been obtained for specimens cut from one tube. 
Otherwise, the maximum variation of impact in 
any one tube from a heat lot or batch is practically 
always about the same as that in any other tube 
from the same heat lot or batch. 

Degree of Control of Transverse Impact 

Considerably more work must be done before the 
degree of control of transverse impact in a practice, 
and throughout industry as a whole, can be defined 
completely. 

Control charts indicate that each tube in a batch 
usually has essentially the same impact quality 


(average and variation) as any other tube from the 
same batch. 

Impact quality differences of considerable mag- 
nitude exist among batches in each practice studied. 
For batches consisting of tubes from only one heat, 
these differences result primarily from a variation 
of batch average transverse impact quality, since 
the difference of variation of transverse impact qual- 
ity in one batch as compared with that in any other 
from the same practice is rarely sufficiently large to 
be of any practical significance. In any one of the 
better practices, impact averages for batches con- 
sisting of tubes from only one heat in a batch varies 
by about 7 ft-lb at a yield strength level of 165,000 
psi. At lower yield strength levels, the differences 
among batch averages in a practice are higher. 

Relation between Yield Strength and 
Transverse Reduction of Area 

Studies were made to determine linear correla- 
tions among the various properties disclosed by the 
tensile test and the impact test in quenched-out and 
tempered gun tubes. It was found that in the yield 
strength range of 95,000 psi to 180,000 psi a good 
linear correlation exists between yield strength and 
transverse reduction of area and that an increase of 

5,000 psi in yield strength causes a decrease of about 
1.5 per cent in transverse reduction of area.^^^ 

This information was used by the Army Ord 
nance Department in the development of specifica- 
tions WVXS-88, WVXS-95, WVXS-131, and the 
U. S. Army Specification 57-106A. In general, use of 
the above relation in specifications encouraged 
each producer of gun tubes to raise his practice 
average for yield strength. This had two beneficial 
effects: (1) it decreased the possibility of accepting 
tubes with a deficiency in yield strength, and (2) it 
drastically reduced the frequency of redraw and of 
requench and draw treatments. The percentage of 
redraw and of requench and draw treatments, 
which at least in one instance was more than 40 per 
cent of the total treatments made, was reduced to 
below 1 per cent. 

Effect of Reheat Treatment (Requench and 
Draw) and Redraw on Transverse Reduction 
OF Area 

Studies of the effect of a redraw and of a re- 
quench and draw on transverse reduction of area 
led to the conclusion that at a given yield strength 


CONFIDENTIAL 


62 


GUNS AND GUN STEELS 


neither a redraw nor a requench and draw improve 
the average RAT of gun tubes, providing they were 
quenched out before the first drawd^^ The effect of 
a redraw and of a requench and draw on transverse 
reduction of area in very heavy tubes is uncertain. 
Laboratory results showed that a redraw improved 
the transverse reduction of area average for one 
tube but had no effect on the average for another 
tube, and a requench and draw did not improve 
the transverse reduction of area average. 

On the basis of the above information, specifica- 
tions were written which encouraged producers not 
to redraw nor to requench and draw tubes which 
fail for transverse reduction of area, unless there 
was evidence that such tubes were improperly heat 
treated. As a result, redraws and requench and 
draw treatments, supposedly made in order to im- 
prove transverse ductility at a given yield strength, 
were reduced very greatly. 

Relation between Yield Strength and 
Transverse Impact 

As previously pointed out, studies were made to 
determine linear correlations among the tensile and 
impact properties in quenched-out and tempered 
gun tubes. It was found that between 95,000 and 

180.000 psi a correlation exists between yield 
strength and transverse impact such that an increase 
of 5,000 psi in yield strength usually results in a 
decrease of 2 ft-lb or more. An excellent correlation 
between yield strength and impact was observed in 
each tube used in correlation studies, but the rela- 
tion was found to vary among tubes. In 40-mm Ml 
and 75-mm M3 seamless tubes, a 5,000 psi increase 
of yield strength results in a decrease of 2 ft-lb in 
transverse impact, while in 75-mm M5 and 76-mm 
tubes from a producer of forgings, a 5,000 psi increase 
of yield strength results in a decrease of 3 ft-lb in 
transverse impact. 

The relationship between yield strength and im- 
pact was taken into account by the Army Ordnance 
Department in writing Specification WVXS-95 and 
U. S. Army Specification 57-106A. As these specifica- 
tions were written at yield strength levels above 

150.000 psi, it is more difficult to meet the mini- 
mum impact requirement than at lower yield 
strength levels. Tubes which usually just meet speci- 
fication impact requirements at 140,000 psi will 
practically always fail if requenched and drawn to 

180.000 psi. 


Effect of Forging Reduction on Transverse 
Reduction of Area 

Studies showed that with increasing forging re- 
duction the average for transverse reduction of area 
increased at first, passed through a maximum (prob- 
ably at below 4; 1 reduction), decreased rapidly, and 
finally decreased more slowly. Also, with increasing 
forging reduction, the average for longitudinal re- 
duction of area at first increased rapidly, reached a 
maximum value (probably at below 4:1 reduction), 
and then remained practically constant.^^^ 

There were those in Army Ordnance who be- 
lieved that the effect of forging reduction on trans- 
verse ductility should be taken into account in spec- 
ifying minimum transverse reduction of area re- 
quirements for the acceptance of those gun tube 
forgings which, if worn out in service, would be 
more likely to fail by progressive stress damage than 
by erosion. For this reason, a higher minimum 
transverse reduction of area quality was required 
for the acceptance of forgings (Specification 57- 
106A). 

Effect of Angle of Test (Relative to Fiber 
Direction) on Transverse Reduction of Area and 
ON Transverse Impact Resistance 

As the angle of test is increased from 0 degrees 
(transverse) to 90 degrees (longitudinal), both aver- 
age impact and average reduction of area values are 
increased. However, up to 20 degrees the increase 
is too small to be of much practical significance.^^® 
Since the twist of seamless tubes at positions away 
from the upset or breech end rarely causes the 
angle between the fiber and the longitudinal axis 
of the tube to be much above 20 degrees, both aver- 
age reduction of area and average impact values for 
nominal transverse specimens cut perpendicular to 
the longitudinal axis of the tube are not signifi- 
cantly different from comparable true transverse 
averages for specimens cut perpendicular to the 
fiber direction. Since the Specification WVXS-131 
used for the acceptance of seamless tubes requires 
specimens to be cut only from muzzle ends of tubes, 
that is, away from the upset breech end, and in 
view of the above considerations, modification of 
Specification WVXS-131 does not appear to be 
needed. 


CONFIDENTIAL 


STEEL FOR GUN TUBES 


63 


3-2-6 Specifications 

Information accumulated by the investigators on 
Project NRC-38 resulted in a better understanding 
of quality needs in gun tubes, especially with re- 
spect to transverse reduction of area, and allowed 
better evaluations to be made of the quality pro- 
duced with respect to yield strength, transverse im- 
pact, and transverse reduction of area than had 
previously been possible. On a basis of this and 
other information available to Army Ordnance, 
specifications for wrought gun tubes were written 
from time to time during World War II. These 
specifications are (1) WVXS-78, (2) WVXS-88, (3) 
WVXS-95, (4) WVXS-131, and (5) U. S. Army 57- 
106 A. 

Specification WVXS-78 

Specification WVXS-67, adopted February 28, 
1942, was found to be inadequate for procurement 
of cannon tubes made from seamless tubes and heat 
treated in continuous furnaces, largely because the 
amount of tensile testing required was excessive. As 
a result of utilizing statistical methods for consider- 
ing tensile data for acceptance and rejection of gun 
tubes, it became possible to develop Specification 
WVXS-78, effective November 3, 1942. This specifi- 
cation has proved highly efficient in obtaining tubes 
of a quality equal to or better than those accepted 
by the older specification and in rejecting tubes of 
unsatisfactory properties. At the same time, it re- 
duces the number of tests required and encourages 
the producer to make tubes of higher minimum 
quality than hitherto in order to take full advan- 
tage of the reduced testing features. The specifica- 
tion is applicable to any method of tube manufac- 
ture, provided the number of tubes per heat is 
large and also that the heat treatment is closely 
controlled. 

Under this specification, tubes of superior quality 
with respect to yield strength and transverse reduc- 
tion of area are accepted in heat lots, whereas tubes 
of much poorer quality which are rejected in heat 
lots often were accepted, at least in part, on an 
individual tube unit basis. 

As a result of replacing WVXS-67 by WVXS-78 
for the acceptance of seamless tubes made between 
November 1942 and February 1944, about 100,000 
tensile tests and between 1,500 and 4,000 heat treat- 
ments were saved. Because of this, personnel were 


released for other duties, equipment was released 
for additional work, the smoothness of operation 
and of scheduling was improved, and cost was re- 
duced. These savings occurred at a critical period 
in World War II when a more fruitful utilization 
of man power and equipment was of utmost impor- 
tance. The operating characteristics of Specification 
WVXS-78 are described in detail in Part I of the 
final report on Project NRC-38. 

Specifications WVXS-88 

This specification was written primarily for the 
acceptance of 37-mm gun tube forgings supplied by 
one company. Tubes having superior transverse 
ductility are accepted in heat lots, while tubes hav- 
ing poor transverse ductility are rejected in heat 
lots, but may be accepted, at least in part, on an 
individual tube unit basis. Tubes are accepted for 
yield strength in batch lots* whenever yield strength 
data indicate that the batch yield strength average 
is far enough removed from specification limits and 
the variation of yield strength in the batch is suffi- 
ciently low to insure that all tubes in the batch 
have adequate yield strengths. However, tubes from 
failed batches are resubmitted for inspection on an 
individual tube unit basis. 

In WVXS-88, the minimum average reduction of 
area requirement was decreased as the yield 
strength of tubes submitted for inspection was in- 
creased. The values written into this specification 
were based on work done on Project NRC-38. 

Since only about 1,300 forgings were submitted 
under Specification WVXS-88 before it was super- 
seded by WVXS-95, the benefits derived from its 
use were small. However, it did result in the saving 
of about 2,000 tensile tests and 500 heat treatments. 
A report on the operating characteristics of Speci- 
fications WVXS-8 and WVXS-95 was prepared.i^^ 

Specification WVXS-95 

This specification was developed for general ap- 
plication to all wrought gun tubes of various types 
and sizes for which yield strength requirements are 
above about 90,000 psi. 

It is estimated that about the same number of 
tubes have been accepted under WVXS-88 and 
WVXS-95 as were accepted under U. S. Army Speci- 
fication 57-105-1 formerly used. However, the aver- 

f A batch lot consists of a group of tubes from the same heat 
which are tempered together. 


CONFIDENTIAL 


64 


GUNS AND GUN STEELS 


age transverse ductility of the tubes accepted by the 
Army Ordnance Department as a result of using 
WVXS-88 and later WVXS-95 is higher, primarily 
because more tubes of low transverse ductility and 
fewer tubes of high transverse ductility were re- 
jected by either WVXS-88 or WVXS-95. 

The magnitude of savings in tensile tests and 
heat treatments which resulted from the use of 
WVXS-95 has not yet been estimated, but they are 
certainly very considerable. 

Specification WVXS-131 

This specification superseded WVXS-78, primar- 
ily because WVXS-78 did not specify an impact 
requirement, nor did it allow the transverse reduc- 
tion of area requirement to change with the yield 
strength of tubes inspected. Both of these features 
were added to WVXS-131. The values written into 
this specification were based on information result- 
ing from the NDRC work on Project NRC-38. 

Specification 57- 106 A 

Since January 1, 1945, U. S. Army Specification 
57-106A has been in effect for the acceptance of steel 
forgings for cannon tubes. Its development resulted 
from the combined efforts of the Army Ordnance 
Department and NDRC investigations. Army Ord- 
nance objectives were to write a single specification 
to cover the purchase of gun tubes which, if worn 
out, would fail by erosion, as well as gun tubes which, 
if worn out, would probably fail by progressive stress 
damage. 

It is believed that U. S. Army Specification 
57- 106 A adequately protects the quality of accepted 
gun tubes, provides an incentive for the producer 
to submit for inspection material of consistently 
high quality, and does not hamper production 
significantly. 

^27 Significance of Angular F racture, 
Homogenization, and Upsetting in 
Relation to Transverse Ductility 

Angular Fracture 

At the start of World War II, the presence or 
absence of angular fractures was one basis for re- 
jection or acceptance of gun tubes on the premise 
that angular fractures indicate low ductility. Since 
investigation of the significance of angular fractures 


revealed that they alone are not indicative of low 
ductility, it is believed that they should not influ- 
ence decisions to accept or reject gun tubes.^^® 

Homogenization 

Studies of the effect of homogenization treat- 
ments on transverse ductility in forgings indicated 
that practical homogenization treatments are un- 
likely to improve the steel quality of forgings.i^o 

Upsetting 

An investigation of the effect of upsetting on 
transverse ductility in seamless tubes showed that 
upsetting raised average transverse reduction of 
area by about 2 or 3 per cent.^^^ 

3 3 IMPROVEMENT IN GUN STEEL 
INGOT PRACTICE 

The seamless process for making gun tubes came 
into use early in 1942 primarily because an ex- 
tremely large number of 40-mm Ml and 75-mm M3 
tubes were required immediately by the Army, and 
it was not possible to supply forgings for such needs. 
Within a short time after tubes were first made by 
the seamless process, rejections owing to bore de- 
fects were excessively high. Actually, before the pro- 
gram for making 40-mm Ml and 75-mm M3 tubes 
was completed, approximately 10,000 tubes had 
been lost owing to bore defects and, unfortunately, 
about half of these were at least partially and often 
completely machined before the defects were found. 
The bore defects referred to here should not be con- 
fused with quench cracks, nonmetallic inclusions, 
or flakes. They usually are quite shallow and are 
believed to be internal ruptures caused by hot work- 
ing. 

As a result of the above situation, two projects 
were established. Project NRC-50 (OD-34-3), Con- 
trol of Basic Open-Hearth Melting Practice for 
Manufacture of Wrought Gun Tubes, at the Tim- 
ken Roller Bearing Company, and Project NRC-39 
(OD-34-3), Improvement in Gun Steel Ingot Prac- 
tice, at Carnegie Institute of Technology. One ma- 
jor objective common to both of these projects was 
the determination of the factors responsible for 
bore defects and the control of these factors so as to 
eliminate, or at least greatly reduce, bore defect 
losses. On Project NRC-50, steel making and pro- 
cessing factors were studied, while on Project NRC- 


CONFIDENTIAL 


IMPROVEMENT IN GUN STEEL INGOT PRACTICE 


65 


39, the work was limited to a study o£ ingot prac- 
tices. Two other major objectives of the work done 
on Project NRC-39 were (1) to determine the effect 
of bore defects in gun tubes on tube performance, 
and (2) to supply information for the establishment 
of standards which would be useful in a quantita- 
tive study of the significance of each factor thought 
to influence the occurrence of bore defects, and for 
the assistance of the Army Ordnance Department 
in standardizing inspection procedures and in set- 
ting up specifications for the acceptance of 40-mm 
Ml and 75-mm M3 gun tubes made by the seamless 
process and containing minor bore defects. While 
such specifications are not at present available, it is 
known that both forged and seamless gun tubes con- 
taining minor bore defects have been accepted. 

Relation Between Ingot Practice 
and Bore Defects 

Investigations of the relation between each of a 
number of factors pertinent to ingot practice and 
the occurrence of bore defects failed to give leads as 
to what changes in practice were necessary to reduce 
bore defect losses in seamless gun tubes made from 
basic open-hearth steel.i^i However, it was observed 
that the maximum frequency of bore defects respon- 
sible for tube losses occurred in steel coming from a 
region of the ingot containing the cone of solidifi- 
cation, and this fact suggested that a change of in- 
got practice, which would lower the cone of solidifi- 
cation so that it would not appear, should reduce 
bore defect losses in guns. It was found that by slow 
cooling of the bottom of an ingot during freezing, 
the cone of solidification could be confined to a re- 
gion of the ingot not contained in the gun tubes. 
Fundamental studies of the solidification of steel in- 
gots indicated the reasons why a slower cooling of 
bottoms should lower the cone of solidification in 
ingots. 

In plant experiments, the slow cooling of ingot 
bottoms during solidification was obtained by use 
of carbon insert insulators. In commercial practice, 
the use of carbon inserts would not be economical. 
However, if desired, a practice could be developed 
which would be economical and would at the same 
time accomplish the end sought. Such a practice 
used by one Canadian steel producer is the pouring 
of steel into molds set on refractory brick bottoms. 


An experiment was planned to demonstrate 
whether, by slowly cooling the bottoms of basic 
open-hearth ingots used for seamless tubes, bore de- 
fect losses could be significantly reduced. However, 
this experiment was not tried for the following 
reasons: 

1. At about the time the experiment was to be 
made, basic electric was substituted for basic open- 
hearth steel for the manufacture of seamless gun 
tubes. Furthermore, the probability of a subsequent 
reversal of this change was quite low, because basic 
electric steel was much more readily available than 
basic open-hearth steel. 

2. The change from basic open-hearth to basic 
electric steel completely solved the bore defect losses 
problem, whereas cooling the bottoms of ingots 
more slowly could probably only cut bore reject 
losses in half at best. 


Effect of Bore Defects on Performance 
of 40-mm Ml and 75-mm M3 Seamless 
Gun Tubes 

During a critical period of World War II in 1942, 
when it was important that gun tubes should be 
produced and inspected as efficiently as possible, 
several hundred seamless tubes per month were be- 
ing rejected. At that time little was known about 
the relation between bore defects and gun tube per- 
formance. Therefore, inspection standards were nec- 
essarily arbitrary. There were those who believed 
that practically all the tubes rejected for bore de- 
fects should have been accepted, and conversely, 
there were some who believed that the psychological 
effect of a visible bore defect in the tube of a new 
gun on the user of the gun justified the rejection of 
the tube regardless of its performance. In this con- 
nection it should be remembered that only a small 
percentage of the tubes rejected had bore defects so 
large as to be noticed readily except by a trained 
observer using a horoscope. 

In order to obtain some information about the 
influence of bore defects on the behavior of seam- 
less gun tubes, a number of such tubes were selected 
and subjected to firing tests.^^^ P’our 40-nim Ml and 
four 75-mm M3 tubes were used for the tests. It was 
estimated that three of the 40-mm and three of the 
75-mm tubes would be classed among the worst 5 per 
cent of the total tubes rejected for bore defects. The 


CONFIDENTIAL 


66 


GUNS AND GUN STEELS 


Other tube of each size was rejected but contained 
only small defects and might even have been accepted 
by other inspectors. No effect on gun life and perform- 
ance was noted in any case. In static detonation of 
projectiles in the region of the defects, the defects did 
not initiate brittle failures. However, the tendency for 
the defect to enlarge on progressive firing was greater, 
the nearer the defect was to the origin of rifling. 

The observation that each of eight tubes rejected 
for bore defects had a normal life and gave a normal 
performance obviously does not justify the assump- 
tion that all the other 10,000 tubes rejected for bore 
defects would behave likewise. It is a fact, however, 
that the probability that such an assumption is true 
is definitely greater because each of eight drawn 
from the 10,000 showed a normal behavior. The 
assumption would be less probable if some of the 
tubes tested had behaved normally and some abnor- 
mally. In evaluating this probability, an effort was 
made to choose six of the worst tubes available. For 
this reason, it is likely that no more than 500 of the 
10,000 or so rejected were as bad or worse than the 
six chosen. 

Control charts of bore rejects indicated a definite 
lack of uniformity in bore inspection which seri- 
ously disturbs any correlation studies and which 
opens the question of the significance of inspection 
methods used for bore defects. 

A study was made of bore defects and a series of 
pictures was obtained covering the usual range of 
defects found in practice. These pictures were dis- 
cussed with Army Ordnance Department personnel, 
and a division yielding four classes of severity was 
agreed upon. This chart provides the means of classi- 
fying, by size and character, the type and possibly 
the severity of any particular defect. 

A method of assigning a quantitative index of 
bore quality was developed, taking into considera- 
tion frequency of occurrence, size and character, 
and possibly severity as well as position of defect 
along the length of the gun tube. This rating was 
used to provide quantitative data on bore quality 
for statistical correlation studies. It also was sug- 
gested to the Army Ordnance Department for pos- 
sible assistance as a means of description in gun 
tube inspection records.^^® 

As a result of cooperative effort between the in- 
vestigators on Project NRC-39 and the Erie Proving 
Ground, a rapid method for bore photography also 
was developed. This was used in practice at the Erie 


Proving Ground to photograph defects in bores be- 
fore and after proof firing. 

3.3.3 Classification of Bore Defects 
in Forged Tubes 

A classification chart for bore defects in forged 
tubes similar to that developed for the classification 
of bore defects in seamless tubes was constructed. 
This was worked out in close cooperation with the 
Armed Services and is on file for future possible use. 

3 4 CONTROL OF BASIC OPEN-HEARTH 
MELTING PRACTICE FOR THE 
MANUFACTURE OF WROUGHT 
GUN TUBES 

The experience of the Timken Ordnance Com- 
pany in processing for gun tubes about 140 open- 
hearth heats of steel from six steel companies, and in 
processing tubes from two piercing sources brought 
out marked differences in the etch quality and physi- 
cal properties resulting from different melting and 
piercing practices. It was indicated that the type of 
inclusions found in the steel is related to the etch 
quality and the physical properties of the steel. 

In order to study this problem. Project NRC-50 
(OD-34-3), Control of Basic Open-Hearth Melting 
Practice for the Manufacture of Wrought Gun 
Tubes, was established in the laboratories of the 
Timken Roller Bearing Company in January 1943. 
The project was confined to studies of the melting 
variables in the making of steel to be used in making 
pierced or seamless gun tubes, as measured by the 
quality of the product as determined by mechanical 
and metallographic tests, acceptance records, etc. 

As it was suspected that the melting practice em- 
ployed in making the steel was one of the more im- 
portant factors affecting gun tube quality, a statis- 
tical correlation was made of the numerous vari- 
ables in melting and pouring practices in an attempt 
to determine the most satisfactory procedure. Cor- 
relation studies of melting and pouring variables 
with resulting etch and bore quality of gun tubes 
were conducted on 353 open-hearth heats of approx- 
imately 120 tons each. Of these, 142 were 40-mm 
heats and 211 were 75-mm heats. Complete logs of 
times, temperatures, additions, preliminary chemi- 
cal tests, etc., were obtained from the producers on 


CONFIDENTIAL 


PREVENTION OF CRACKING IN GUN TUBES 


67 


each heat. Altogether, 8 different correlation studies 
were made, each on a different group of 40-mm or 
75-mm heats.^^^’^'^^’^^^ The principal conclusions 
derived from these studies are as follows: 

1. Statistical correlation studies of 353 gun heats 
indicate that certain variables in melting and cast- 
ing practice affect the etch and bore rejections. 

2. The control of the oxidizing condition of the 
slag, particularly during the finishing period of the 
heat, has a pronounced effect on both alloy losses 
and gun quality. The more highly oxidizing and 
active slags cause greater loss of alloys and tend to 
produce poorer gun steel (as judged by increased 
gun rejections for macroetch and bore defects). 

3. More frequently than not, heats with turnings 
in the charge result in higher gun rejections. 

4. Two different types of melting practices em- 
ployed by the same producer of 40-mm gun heats 
have been found to yield marked differences in re- 
sultant gun quality. Alloy losses and rejections are 
smaller on the heats melted under less oxidizing 
conditions. 

5. FeCr additions to the bath are favored over 
Chrome-X additions to the ladle. Also, CaSi addi- 
tions to the ladle are favored over FeSi additions 
to the ladle. 

6. Control of tapping and pouring temperature 
is most important. A medium pouring temperature 
is most satisfactory. Skulled or cold heats are defi- 
nitely unsatisfactory. 

7. Heats poured into ingots with “C” and “D” 
hot tops tended to be better than those poured into 
clay-topped ingots. There is an indication that 
straight pouring is preferable to back pouring. 

8. Exceptionally short and long holding times of 
heats after pouring are more frequently undesirable. 
Ingots of approximately 6,000 lb in weight should 
be held at least 1 hour before moving and prefer- 
ably should be charged into the soaking pits within 
4 hours after pouring. 

The rolling and piercing practices were also sus- 
pected as having some effect on the quality of the 
guns. Studies of these practices were made,^^^ with 
the following conclusions: 

1. Heats which are direct rolled from ingots into 
8 in. round piercing billets for 75-mm guns show 
better gun quality than those that are double con- 
verted into billets. Direct-rolled 40-mm heats, how- 
ever, do not show any appreciable superiority over 
double-converted heats. 


2. The direction of piercing a gun tube, whether 
with or against the original herringbone pattern in 
the ingot, has not been found to affect the quality 
of the gun tube. 

3. Normal variations in both drawing tempera- 
tures of billets from the piercing mill reheat furnace 
and in electrical power consumed in the piercing of 
gun tubes showed no appreciable correlation with 
the resulting gun tube. 

4. Piercing of 40-mm gun tubes with longer plugs 
is favored over shorter plugs. The greater surface 
area of the longer plug increases the amount of hot 
working on the inside diameter of the tube. 

5. With the exception of the method of rolling 
ingots into billets, factors which tended to better 
75-mm gun steel quality also bettered 40-mm gun 
steel quality. 

6. The inherent quality of gun steel heats which 
is attained during melting and casting is by far 
the most important factor affecting gun tube qual- 
ity. The most ideal rolling and piercing conditions 
cannot produce good quality guns from a heat 
which, for example, was poured very cold. 

The second phase of the research program was 
the determination of the relation between the RAT 
and the several inclusion rating factors of good ver- 
sus bad heats of steel.i^®’^'’*-^ Based on over 1,100 in- 
dividual specimens from 123 heats of steel, a corre- 
lation was established between both quantity and 
type of nonmetallic inclusions and the RAT ob- 
tained in basic open-hearth Cr-Ni-Mo steel proc- 
essed in 40-mm and 75-mm seamless gun tubes. 
Basing the inclusion rating on the Timken chart, 
for each unit of the rating chart in the direction of 
dirtier steel, the average or peak of the distribution 
curve decreases about 5 per cent RAT in 75-mm 
tubes, but less in 40-mm tubes. With the same total 
inclusion content, the stringer-type inclusion is more 
detrimental than the nonstringer type. 

35 PREVENTION OF CRACKING 
IN GUN TUBES 

A study of data from the manufacturers of gun 
tubes showed that in one year, September 1, 1942, 
to September 1, 1943, about 2,000 tubes of sizes vary- 
ing from 40-mm to 8 in. were cracked during heat 
treatment. For this reason, in February 1944, Proj- 
ect NRC-80 (OD-34-3), Prevention of Cracking in 
Gun Tubes, was established at Carnegie Institute of 


CONFIDENTIAL 


68 


GUNS AND GUN STEELS 


Technology in order to develop a suitable test for 
cracking susceptibility, to determine causes of 
quench cracking, and to propose practical steps to 
reduce losses from cracking to a minimum. 

3.5.1 Development of Test for Cracking 
Susceptibility 

A test was developed for determining the crack- 
ing susceptibility of gun tubes.^^® The basic prop- 
erties of this test are provided by a series of disks 
cut from the bore of a gun tube and V-notched on 
the ID to induce cracking during a quench. The 
notched test disks are quenched in a jig in such a 
way that rapid cooling occurs on ID and OD sur- 
faces only, that is, heat is abstracted from the disk 
wall radially. Cracking susceptibility is measured 
by an index value. As this value increases, the crack- 
ing susceptibility decreases. Notched disks from a 
portion of tube having a cracking susceptibility of 
1/4 in. would sometimes show notch cracks if the 
ID notches in the quenched disks were i/4 in. deep. 
(The root of notch is 0.012 in. and angle of notch 
is always 30 degrees.) Disks with 3/ 16-in. notches 
would rarely ever crack when quenched, and disks 
with 5/ 16-in. notches practically always would 
crack. The reproducibility of the test is probably 
good to within plus or minus 1/16 in. of the index 
value. 

No significant correlation was found to exist be- 
tween determined index values and percentages of 
tubes cracked per heat. The failure to find such 
a correlation probably resulted from inadequate 
sampling rather than from a lack of sensitivity of 
the test. When a treatment is used which causes all 
the material so treated to crack much less easily, 
then it is known that such a treatment raises the 
index values as determined in the cracking suscep- 
tibility test. For example, prebore quenching raised 
the ID index value determined by the cracking test 
and lowered cracking losses as determined by one 
company. 

Causes of Quench Cracks 

Quench cracks occur when tensional stresses are 
high enough to cause rupture. If such stresses are 
sufficiently high, cracks occur in steel of superior 


quality, and if steel quality is sufficiently poor, rela- 
tively low stresses cause cracking. Unfortunately, it 
is often quite difficult to determine whether a 
quench crack results from a change of stress pattern 
(heat treatment), poor steel quality, or a combina- 
tion of both. (Other potential causes listed below as 
“remedies” also may be of considerable importance.) 

Tentatively, it was concluded that cracking sus- 
ceptibility is a heat characteristic. This means that 
even if heat treatment were held constant within 
the smallest limits of variation possible, cracking 
losses per heat would still be expected to vary 
markedly from heat to heat. The primary cause of 
the variation of cracking susceptibility among heats 
has not yet been discovered. Tubes not normalized 
tend to crack more easily than do those which are 
normalized, and tubes of relatively high carbon 
crack more easily than do those which have lower 
carbon content. At present, however, effects of 
normalizing and carbon content, within the range 
studied, are believed to be quite minor causes of 
cracking. Ingot bottom weakness (region of cone of 
solidification) is believed also to be a cause of crack- 
ing in gun tubes. Quenching from too high a tem- 
perature and quenching for too long a time showed 
evidence of causing quench cracks, but within the 
normal temperature and time ranges used in com- 
mercial practice, these factors too are only of minor 
significance from a practical point of view. 

Remedies for Reducing Quench 
Crack Losses 

The remedy to be applied for the purpose of 
reducing quench crack losses depends on whatever 
the major cause of cracking happens to be in the 
particular practice considered. This is not the same 
for each practice. 

Quench-crack losses may be reduced by (1) pre- 
bore quenching, (2) using basic electric instead of 
basic open-hearth steel, (3) tempering as soon after 
the quench as possible, (4) using the lowest carbon 
content steel possible which will give the desired 
yield strength after the quench and temper, (5) 
choosing a composition which gives to steel little 
more than the hardenability desired and as high 
an Ms temperature as possible, (6) using a normal- 
izing treatment before heating for the quench, (7) 
quenching from the lowest temperature possible 


CONFIDENTIAL 


HEAT TREATMENT OF GUN STEELS 


69 


which will give desired properties after the quench 
and temper, (8) holding in quenching medium for 
optimum time, depending upon the gun type, size, 
and heat-treatment practice, (9) improving loading 
arrangement of tubes in batches to be quenched 
so that each tube is more uniformly quenched, and 
(10) improving the water circulating system. 

In referring to remedies for reducing quench- 
crack losses, an attempt has been made to arrange 
them in order of effectiveness. It is believed that 
prebore quenching, which heads the list, is so effec- 
tive and so generally applicable that its proper use 
in any practice is likely to reduce cracking losses to 
insignificance. One company lost four out of twenty- 
four 8-in. howitzers owing to quench cracks when 
the tubes were quenched simultaneously on both ID 
and OD surfaces before being tempered, but lost 
no tubes at all out of 172 when the bore was 
quenched for 2 minutes before ID and OD surfaces 
were quenched simultaneously. 

Effects of each of the other variables seem to be 
beneficial when applied to one practice but of ques- 
tionable value when applied to another practice. 
Considerable work remains to be done before the 
relative usefulness and applicability of the remedies 
mentioned above can be quantitatively evaluated. 
Work on this problem is being continued under 
an Army Ordnance Department contract. 

3.6 HEAT TREATMENT OF GUN STEELS 

It was made clear in the previously described 
studies that different heats of gun steel require 
different tempering temperatures in order to de- 
velop the required yield strength, and that each 
heat may have to be treated as a separate batch, 
rather than allowing tubes from different heats to 
be mixed, tempered at some arbitrary temperature, 
and individually tested with the result that many 
tubes have to be retreated. Thus, the selection of 
the proper tempering temperature and time for 
tempering each heat becomes an important step. 

It is well known that equivalent tempering can 
be accomplished at a relatively low temperature for 
a long time or at a relatively high temperature for 
a short time. If the tempering furnace has good 
temperature uniformity and if the charge is so 
placed that all parts of it have equal ingress of 
heat, that is, if the charge is properly loaded into 
the furnace, the higher temperature and shorter 


time make for more rapid production. The degree 
to which the quenched steel is tempered is well 
indicated by the hardness. 

For best properties in gun tubes (and in homo- 
geneous armor), the steel must be quenched fully 
to martensite before tempering. If, during quench- 
ing, there is partial transformation at a relatively 
high temperature of austenite to ferrite and pearlite, 
or at a lower temperature to a range of acicular 
structures known as bainite, and if part of the 
austenite is thus used up in forming these structures, 
only a portion of the austenite remains to form the 
desired martensite at the low temperature at which 
this change occurs. On tempering, the desired tem- 
pered martensite (secondary troostite or sorbite, 
according to the tempering temperature) is inter- 
spersed with the ferrite-pearlite, or with tempered 
bainite, or both. These tempered nonmartensitic 
structures may have a hardness close to that of the 
desired tempered martensite, or they may be present 
in too small an amount to show up in the hardness 
determination. Their presence, however, is revealed 
by examination under the microscope. Such struc- 
tures noticably depreciate the mechanical proper- 
ties, and the notched bar impact resistance at low 
temperatures. 

When nonmartensitic transformation products 
appear on quenching, the steel is said to be slack 
quenched. Failure to produce martensite results 
from too low a rate of cooling. The outside of a 
quenched gun can be chilled rapidly enough in the 
quench to make it martensitic, but, unless the au- 
stenite is sluggish enough to stand a lower rate of 
cooling without transforming to nonmartensitic 
structures, the center or even the outside partly 
transforms to these nonmartensitic structures. Plain 
carbon steel has nonsluggish austenite; in large sec- 
tions, the center does not transform to martensite 
but rather to one or both of the nonmartensitic 
structures. 

Carbon steel, therefore, is relatively shallow hard- 
ening to different degrees according to the carbon 
content. A drastic quench, such as water under 
pressure, brine, or other water solutions, cools the 
outside more rapidly than does oil, and slightly 
greater depth hardening can be obtained in carbon 
steels by water quenching instead of oil quenching. 
But even water-quenched carbon steel will not 
harden properly all the way through in sections 
corresponding to those of gun tubes, such as 40-mm, 


CONFIDENTIAL 


70 


GUNS AND GUN STEELS 


75-mm, and larger. Hence, an alloy steel must be 
used in which one or more alloying elements are 
present to make the austenite sufficiently sluggish 
so that it does not transform to nonmartensitic 
structures. Such steels are more deeply hardening. 
As the section to be quenched increases, more alloy, 
and preferably two or three rather than just one 
alloying element, is required. 

The hardenability of steel is evaluated by the now 
familiar Jominy test, in which one end of a cylinder 
is quenched by water under pressure, the other end 
not being touched by the water. After quenching, 
the distance back from the quenched end at which 
the desired hardness and structure have been ob- 
tained measures the hardenability of the steel. It is 
necessary to note that commercial evaluation of the 
Jominy test is often made on the basis of the dis- 
tance from the end of the test bar at which 50 per 
cent martensite is obtained because at that per- 
centage, in plain-carbon steels, there is an easily 
discerned difference in etching behavior. But 50 
per cent martensite is slack quenching and the 
structure less desirable for ordnance purposes, com- 
pared to a fully martensitic structure. In gun steels 
a drop of five points in Rockwell C hardness is 
taken as an approximate criterion, but even this 
does not insure absence of large amounts of bainite. 

Jominy hardenability testing for quenched hard- 
ness tells nothing about the structure or the fitness 
for guns or armor. The standard bar may show 
little drop in hardness clear out to the air-cooled 
end, yet that steel fails to harden at the center in 
the quenching of a heavy gun. It is necessary to 
evaluate alloy steels being considered for guns and 
armor in much more thorough fashion. 

Chemical composition is only a means to an end 
and of no value in itself. Many combinations of ele- 
ments and amounts of elements can be utilized 
equally well to avoid slack quenching. But, for con- 
servation of available supplies of alloying elements, 
it makes a great difference whether a composition is 
chosen with just enough of readily available ele- 
ments, or whether, through ignorance of the exist- 
ence of substitutes, the composition calls for large 
amounts of critical or strategic alloys. Moreover, 
since the availability of different alloying elements 
varies from time to time and, under some»conditions, 
may not be predictable, there is need not only for 
evaluation of substitute compositions that appear 
logical under the supply conditions of the moment 
but also for clarification of the methods of evaluation 


so that any other suggested composition can be 
promptly put through its paces to determine how 
well it avoids slack quenching. 

3.6.1 Time -Temperature- Hardness 

Relations 

To secure fundamental data on the thermal 
characteristics of gun steels from which improved 
heat-treatment cycles might be developed by gun 
manufacturers. Project NRC-36 (OD-34-3), Metal- 
lographic and Physical Properties of New Types of 
Gun Steels, was established at the University of 
Notre Dame du Lac in October 1942. 

The initial phase of the investigation was a study 
of the time-temperature-hardness relationships of a 
typical gun steel. If one assumes that in actual prac- 
tice the tempering time will be held constant and 
only the temperature adjusted to the needs of the 
particular heat, the determination of the correct 
temperature can be made by tempering for a stand- 
ard time a properly quenched, long specimen in a 
furnace in which there is a temperature gradient 
covering the temperature range that is of interest, 
determining the hardness gradient thus produced, 
and from the results selecting the correct tempera- 
ture to produce the required hardness. With two or 
more such gradient furnaces, operated for different 
tempering times, the time-temperature relations can 
be worked out. 

However, it was found that it was not necessary 
to make the test quite so elaborate, since use could 
be made of an experimentally ascertained relation- 
ship by which, when the reciprocal of the absolute 
temperature is plotted against the natural logarithm 
of the reciprocal of the time, a straight line results 
for the observed points corresponding to any chosen 
hardness level. The straight lines for each hardness, 
that is, 40, 35, and 30 Rockwell C, are practically 
parallel. Then, if specimens are tempered at one 
fixed temperature but for two or more times, and 
if the results are plotted, the time-temperature-hard- 
ness relations are made evident. They can be ex- 
pressed for each hardness level in terms of the inter- 
cept and slope of the plotted line. Once the slope 
is known for a given type of steel, a single specimen 
from each heat can be tested at one time and tem- 
perature, the result plotted, and a straight line 
drawn parallel to the standard slope. Thus, for ex- 
ample, by tempering specimens at 1175 F for 1 hour, 
it was shown that to produce the specified hardness 


CONFIDENTIAL 


HEAT TREATMENT OF GUN STEELS 


71 


for 40-mm tubes for four different heats of the same 
type of steel would require tempering temperatures 
of 1150, 1160, 1170, and 1180 F. These would then 
meet the hardness specifications exactly. If all had 
been tempered at the average temperature of 1165 
F, the heats that needed 1150 F and 1180 F would 
not have been tempered correctly.^ 

This test method for determining the correct 
tempering temperatures for fully hardened and tem- 
pered gun tubes was adopted by the Timken Roller 
Bearing Company, a manufacturer of seamless gun 
tubes, and resulted in the development of an im- 
proved heat treating practice. In this practice, which 
was fully automatic and continuous, the only vari- 
able which could be adjusted easily was the temper- 
ing temperature. By the use of this test method, the 
optimum tempering temperature of each heat of 
steel was employed. This resulted in a substantial de- 
crease in the number of rejections and a correspond- 
ing increase in production of seamless gun tubes. 

To extend the use of this method of predicting 
optimum tempering temperatures to other types of 
gun steels being used. Project NRC-85 (OD-34-3), 
Time-Temperature-Hardness Relations in New Gun 
Steels, was established in June 1944 at the Univer- 
sity of Pittsburgh. 

This investigation covered studies of eight se- 
lected gun steels, one of which was similar to that 
upon which the original test was developed, as well 
as an armor composition which was suggested by 
Watertown Arsenal for a comparison with the gun 
steels. 

Earlier findings for steels of 0.30 to 0.60 per cent 
carbon were corroborated.^®--^®^ A lower carbon 
steel behaved somewhat differently, but in the car- 
bon range used in most guns and armor, the general 
patterns of behavior on tempering were so similar 
that predictions as to temperability, and the effect of 
alloying elements upon it can be made with consider- 
able accuracy and with a minimum of experiment. 

These investigations of time-temperature-hard- 
ness relations demonstrated principles applicable to 
any heat of that steel, or to any heat of any other 
steel that shows complete martensitic hardening on 
quenching in the sections obtaining in the gun 
tubes being made. 

3-6.2 Slack Quenching 

Because of the very different behavior of gun 
tubes with slack-quenched and tempered structures 


and the limited knowledge of these structures, the 
investigation of the heat treatment of gun tubes at 
Notre Dame, Project NRC-36, was extended to in- 
clude a systematic study of the tempering charac- 
teristics, metallographic structures, and physical 
properties of gun steels with slack-quenched struc- 
tures. It has been found generally that slack- 
quenched gun tubes have inferior physical proper- 
ties, especially with respect to impact strength. 
Probably the most important information relevant 
to this problem is the time for initial decomposition 
at any temperature and the nature of the product 
or products of decomposition at that temperature. 
Since a systematic attempt to study slack-quenched 
structures must be preceded by a thorough knowl- 
edge of the S-curve for the steel under consideration, 
S-curves for ten typical gun steels were determined 
with particular emphasis on the temperature of 
martensite formation.^^i 

The behavior of a steel in respect to retention of 
austenite is mapped traditionally by the S-curve. 
This is obtained by the isothermal method, that is, 
the steel is heated until it becomes austenitic, then 
immersed in a fused salt or fused lead bath, held 
there at a definite temperature for a definite time, 
and then quenched in order to transform to mar- 
tensite the austenite not previously transformed to 
ferrite, pearlite, or bainite. The piece is then exam- 
ined for hardness and structure. With enough data 
taken at various different times of residence at tem- 
perature, a behavior chart is made, showing the 
range of time and temperature the austenite can 
endure without changing over to a nonmarten- 
site product. This chart gives a correct picture for 
the behavior under just such isothermal conditions, 
but the picture is incorrect for quenching conditions 
where the temperature is continually dropping. 
Empirical corrections have been suggested, but 
since these are not generally applicable with any 
degree of exactness, the use of ordinary S-curves in 
evaluating gun steels has distinct limitations. In the 
experimental examination of methods of evaluating 
the true slack-quenching behavior, it appeared that 
bainite is formed in two stages and that austenite 
retained with it is persistent, that is, resists decom- 
position on tempering after quenching, but on 
cooling from the tempering temperature it may 
transform to fresh, hard, brittle martensite. 

In this investigation it was tentatively suggested 
that the presence of this brittle, untempered mar- 
tensite, as well as the recognized deleterious presence 


CONFIDENTIAL 


72 


GUNS AND GUN STEELS 


of ferrite or bainite, is partially responsible for 
much of the poor mechanical behavior of a slack- 
quenched structure. If this is true, a second temper- 
ing to temper this late-formed martensite should help. 

In 10 steels of such hardenability as to be of some 
interest for guns, this same two - bainite - reaction 
phenomenon was noted. All the steels contained 
0.30 to 0.40% C. Some of them had li/ 2 % Mn, 2 
to 2.75% Ni, 0.60 to 0.80% Cr, 0.25 to 0.40%, Mo, 0 
to 0.10% V. Others, with no or low nickel, contained 
0.90 to 1.00% Cr, 0.20 to 0.55% Mo, 0 to 0.12% V. 
One had no Ni, 1.00% Cr, 1.00% Mn, 0.50% Mo, 
0.10% V. Regular S-curves were drawn for these 
on the basis of isothermal holding and resultant 
structure and hardness, and dilatometer tests. Some 
information was obtained on the speed of the first 
and second bainite reactions as a function of tem- 
perature. 

This work was insufficient to evaluate the possi- 
bilities of the steels as gun steels, inasmuch as to 
bring out those possibilities would require slack 
quenching, double tempering, and determination 
of mechanical properties at the time maximum at- 
tention had to be directed to guns requiring thor- 
ough quenching. The work indicates that evalua- 
tion on the basis of S-curves, as ordinarily obtained, 
may eliminate steels that, heat treated in the light 
of the evidence obtained, would produce good qual- 
ity guns and be economical of strategic alloying 
elements. 

3 7 FATIGUE STRENGTH OF GUN STEEL 

At the request of the Army Ordnance Depart- 
ment, the Metallurgy Section of the former Division 
B, NDRC, established Project B-189 (OD-34-10), 
Fatigue Strength of Selected Gun Steels Under 
Combined Stress, at the University of Michigan in 
October 1941. The program covered combined-in- 
phase bending and torsion fatigue tests. A testing 
machine designed for a speed of 3,600 rpm was con- 
structed and a pilot test was made on SAE X4340 
steel. The tests were based originally on the im- 
portance of determining characteristic relationships 
at the endurance limit (10,000,000 cycles) and, for 
this reason, the data available for the determina- 
tion of any definite trend at higher stresses are 
insufficient. 

Since the results of this study were highly uncer- 
tain and since it appeared that the effort could be 
applied to problems of more urgent importance in 
the war effort, the project was terminated in Sep- 


tember 1942, and the testing machine was shipped 
to Watertown Arsenal for possible future use. 

The few data obtained on this investigation may 
have a bearing on the multidirectional stress prob- 
lems met in the ship failure problem, discussed in 
Section 6.2.3 of this report. The results tentatively 
indicated that when repeated bending is predom- 
inant failure tends to be in the normal brittle 
fashion of the ordinary fatigue test, but changes 
to a ductile failure when repeated torsion is pre- 
dominant. 

3 8 DEVELOPMENT OF NEW GUN 
STEELS 

In February 1944, the Research Group, Subcom- 
mittee on Gun Forgings, Ferrous Metallurgical Ad- 
visory Board, Army Ordnance Department suggested 
the establishment of Project NRC-81 (OD-34-3), 
Development of High - Strength Gun Steels. Al- 
though the OSRD contract was placed with the 
Vanadium Corporation of America, the research 
program was a cooperative effort. The heats of 
steel, the compositions for which were selected by 
the War Metallurgy Committee Project Advisory 
Committee, were made by the Midvale Company, 
the specimens were prepared and heat treated by 
the Vanadium Corporation of America, and the 
tests were made by the United States Steel Corpora- 
tion Research Laboratories, by Watertown Arsenal, 
and by the Vanadium Corporation of America. 

The purpose of the search for new gun steels 
was to find a steel reasonably amenable to regular 
steel-making processes, forging, etc., by which the 
yield strength now consistently obtained in 75-mm 
guns 140,000 to 170,000 psi, and in 76-mm guns, 
150,000 to 180,000 psi, might be reached in larger 
sizes. 

The logical way to reach this goal is through the 
development of a deep-hardening steel with an S- 
curve such that bainite is avoided and martensite 
produced at the center of the section of quenching. 

The same approach was taken here as in the 
armor projects^^^’^-^ discussed in Section 2.3 of 
this report, that is, systematic variation of composi- 
tion and determination of the resultant harden- 
ability and S-curves. In the gun steel work, the level 
of carbon content was higher than that in the 
armor projects, and only the ordinary alloying ele- 
ments, manganese, nickel, chromium, molybdenum, 
and vanadium, were utilized. The study of boron 
additions was to be deferred until the preferable 


CONFIDENTIAL 


INDEX OF REPORTS ON GUNS AND GUN STEELS 


73 


combinations of the other elements were ascer- 
tained. 

Attention was directed especially to the crucial 
part of the S-curves, that just above the temperature 
of the start of martensite formation Ms, at which the 
too early formation of bainite would introduce unde- 
sirable properties. Among other treatments, isother- 
mally treated notched bar impact specimens that 
had been held for varying times just above the Ms 
point were quenched and tempered, cooled, and 
tempered back to 40 Rockwell C. This gives an 
opportunity for retained austenite to transforrh to 
martensite on cooling from the hrst tempering, and 
this martensite in turn to be tempered. The impact 
values on specimens so treated serve as an indication 
whether bainite has been produced in the isolther- 
mal treatment. This simulates the quenching cycle 
of the so-called “martempering” process which holds 
a heavy section just above the Ms point for temper- 
ature equalization before quenching. 

Jominy curves, S-curves, Ms temperatures, and 
impact values after the treatment discussed above 
were determined and reported^®^'^®® for some two 
dozen compositions, some of which showed promise. 
The work was of a preliminary nature, aimed to 
pick out the most promising lines of attack. It will 
need to be carried further and ultimately to be 
supplemented by a study of boron additions to the 
more promising compositions. 

The basic metallurgical data such as Jominy hard- 
enability curves and S-curves for the SAE and the 
NE steels that serve for the smaller sections made 
from heat-treated steels are available in published 
literature, but no published survey of steels for use 
in heavy sections compares in completeness with the 
studies of heavy armor and large guns made in 
these NDRC projects, incomplete and preliminary 
as they still are. 

It is understood that research of this nature will 
be continued by the Army Ordnance Department 
in the research laboratory at Watertown Arsenal. 

3 9 PRESENT STATUS OF RESEARCH 
ON GUN STEELS 

Further work was needed on several phases of 
the NDRC research program on gun steels when 


the principal projects were terminated in June 1945 
in accordance with the NDRC demobilization plans. 
This was recognized by the Office of the Chief of 
Ordnance, and arrangements were made to have 
the projects conducted at Carnegie Institute of 
Technology transferred to direct Army Ordnance 
contracts. The projects concerned are Project NRC- 
38, Improvement in Wrought Gun Tubes; Project 
NRC-39, Improvement in Gun Steel Ingot Practice; 
and Project NRC-80, Prevention of Cracking in 
Gun Tubes. These continuing phases of the gun 
steels research program were mentioned as each 
topic was discussed in this report. 

Other work also seems to be desirable. Cracking 
is still a major factor in rejection, and the causes 
have not been determined nor have methods been 
devised to determine adequately the propensity to- 
ward cracking. 

The possible beneficial effect of double tempering 
of steels with retained austenite should be explored 
further, since it might be an important factor in 
the selection of alternate steels. 

Search should continue for alternate steels that 
are not too prone to injury on slack quenching and 
yet do not call for large amounts of strategic alloys; 
and, since the supply of any one alloy may fluctuate 
widely, different alternates should be worked out 
and comprehensive data put on the shelf to be 
taken down as need arises. Regardless of the alloy 
situation, compositions or treatments less prone to 
cracking on quenching and producing better tough- 
ness at high yield strengths are needed. 

3 10 INDEXING OF DIVISION 18 REPORTS 
ON GUNS AND GUN STEEL 

To make the research information in the many 
Division 18 reports on guns and gun steels more 
readily available and to enhance the usefulness of 
the reports, the librarians of the Research Informa- 
tion Division of the War Metallurgy Committee 
prepared a comprehensive index of all of the re- 
ports issued. This index^oT provides a subject index 
of the information obtained on the topics studied 
and a listing of the projects with the serial numbers 
of the reports submitted on each. 


CONFIDENTIAL 


Chapter 4 

AMMUNITION 


4.1 INTRODUCTION 

F ive investigations were conducted on materials 
for three components of ammunition; armor- 
piercing shot, cartridge cases, and driving bands. 
These studies were made at the request of the Office 
of the Chief of Ordnance and were but phases of the 
extensive ammunition programs being conducted by 
the War and Navy Departments. 

42 ARMOR-PIERCING SHOT 

As one phase of the alloy conservation program, a 
study was made of the use of the special nonalloy 
steels for the manufacture of armor-piercing capped 
shot to obviate the use of critical alloys. Since the 
use of special addition agents in plain carbon steels 
had been investigated by the Buick Motor Division 
of General Motors Corporation during the period of 
automotive production and had been applied suc- 
cessfully in the manufacture of various high duty 
parts. Project NRC-37 (OD-107), Investigation of 
the Use of Special Non-Alloy Steels for Armor-Pierc- 
ing Capped Shot, was established at Buick. 

The initial phase of this research program was 
confined to studies of steels treated with additions of 
Grainal (a complex deoxidizing agent containing 
vanadium, calcium, aluminum, and boron) replac- 
ing the usual alloying elements used for the manu- 
facture of the WD-4150 modified 37-mm projectile. 
Various modifications and heat treating cycles were 
tried to determine which would produce a projectile 
having the best ballistic properties. The tests con- 
ducted on the steel from which each lot of projectiles 
was machined included chemical, tensile, Izod im- 
pact, Jominy hardenability, grain size, and inclusion 
counts. Samples of each completed lot of projectiles 
were examined for hardness pattern and microstruc- 
ture and then submitted to the Aberdeen Proving 
Grounds for ballistic tests. The results indicated that 
satisfactory projectiles could be made of Grainal- 
treated nonalloy steels as the performance of two of 
the experimental lots exceeded that of the standard 
projectiles with which they were fired.^®® 

The second phase of the research program was con- 


cerned with the development of a shot with superior 
ballistic properties from both nonalloy and alloy 
steels. One of the most significant difficulties en- 
countered in the performance of 37-mm AP projec- 
tiles was the destruction of the projectile ogive upon 
impact. This was not so common with AP projectiles 
of larger calibers. Various modifications in process- 
ing, together with a number of different steel com- 
positions, were tried in an effort to improve shot 
performance. Among these were the carburization of 
the ogive, austempering, design changes of the pro- 
jectile body and cap, and refinement of the induction 
base draw and hardening cycles. A projectile with 
the rough contour of the ogive formed by forging 
which had passed through a li/^-in. face-hardened 
armor plate intact was examined, and a lamellar 
pattern in the hardened zone was found. This dis- 
closure subsequently influenced all experimentation 
on the project. The investigators believe that the 
most significant development of the work on this 
phase of the program is the importance of the heat 
treating cycle. The ballistic performance of each of 
six experimental lots was outstandingly successful. 
These lots were composed of three steels of widely 
different compositions, each of which had been heat 
treated with special reference to the particular mate- 
rial involved. 

It appears that a boron-treated simple manganese 
steel NE-9262 boron-treated NE-9465, or other steels 
of similar hardenability, will serve equally well for 
the fabrication of AP shot, structure and hardness 
gradient being the important factors rather than 
composition. As the work on this project was limited 
in scope, it should be correlated with the mass of 
information obtained in the production and testing 
of the millions of AP shot of this and other sizes 
produced by various contractors who applied various 
types of heat treatment to secure the desired graded 
hardness. 

4 3 CARTRIDGE BRASS 

Three investigations relating to stress-corrosion 
cracking of cartridge brass were undertaken at the 
request of Frankford Arsenal. These covered (1) the 


74 


CONFIDENTIAL 


CARTRIDGE BRASS 


75 


prevention of stress-corrosion, (2) the detection and 
elimination of internal stresses contributing to stress- 
corrosion, and (3) the effect of volume changes asso- 
ciated with phase changes. 

4*3.1 Stress-Corrosion 

In the forming of brass cartridge cases, internal 
stresses are introduced. Unless these stresses are com- 
pletely relieved, a residual stress remains. Under 
some corrosive conditions arising from the powder 
inside the case or from the atmosphere outside, stress- 
corrosion cracking may occur which spoils the case. 
Old ammunition which has been in storage may be- 
come useless because of this. This phenomenon was 
at one time referred to as season-cracking, but with 
subsequent knowledge that many alloys crack under 
corrosive conditions which tend to attack grain boun- 
daries when the alloy is under tensile stress (either 
residual internal stress or externally applied stress), 
the term stress-corrosion has been adopted. The 
problem is as old as the brass cartridge case, but it is 
still a continuing problem. 

Prevention of Stress-Corrosion 

Since stress-corrosion cracking requires both stress 
and corrosion, avoidance of either factor, stress or 
corrosion, will prevent it. Of course, prevention of 
any sort of corrosion, whether it produces cracking 
or not, is worth while. 

Under their control number OD-25, the Office of 
the Chief of Ordnance requested NDRC to investi- 
gate a variety of coatings to supplement Frankford 
Arsenal’s work on organic coatings. Project NRC-27, 
Prevention of Stress-Corrosion Cracking of Cart- 
ridge Brass by Protective Coatings or Surface Treat- 
ments, was established in the research laboratories 
of the New Jersey Zinc Company. 

Since cartridge brass is composed of copper and 
zinc, electroplating the case or the brass strip from 
which it was formed with one of these metals is a 
possible method of protection. 

To study the protective value of these and other 
coatings, tensile specimens of stress-relieved cartridge 
brass strip were dead-weight loaded to 15,000 psi 
and subjected at 99 F to an atmosphere of 82 per 
cent relative humidity containing 90 per cent air, 
20 per cent ammonia gas, and a small addition of 
carbon dioxide. This is a standard accelerated test, 


the results of which correlate well with actual service 
exposures. Unprotected specimens break in 5 hours 
under the test conditions. 

Copper is attacked by ammonia under these con- 
ditions, but there was a possibility that the attack 
could be slowed down. However, the results of the 
investigation indicated that thin coatings of copper 
give no benefit and a coating 0.0012 in. thick only 
delays failure about 50 hours, whereas a zinc coating 
of the same thickness delays failure about 470 hours. 
Even thin coats of electroplated zinc prove effective 
and, moreover, extend electrochemical protection to 
bare areas where the zinc coating had been scratched 
away. The effectiveness is proportional to the thick- 
ness of the zinc coating. The corrosive atmosphere 
slowly removes zinc, but the zinc exercises protection 
as long as even a thin coating remains and as long 
as bared areas from which zinc has been completely 
removed are not too large. Thick zinc coatings pro- 
tect larger bare areas than thin ones. 

The applied stress is not a major factor. Stresses 
ranging from 10,000 to 24,000 psi do not affect the 
breaking time of zinc-coated specimens. That is, as 
long as the coating prevents corrosion of the brass, 
stress-corrosion cracking does not occur. After cor- 
rosion of the zinc coating exposes a brass area too 
large for electrochemical protection to be effective, 
the brass behaves as it would without zinc, that is, 
brass containing internal stress fails rapidly while 
the stress-relieved material stands up. 

Zinc slowly diffuses into brass at somewhat elevated 
temperatures. Zinc coatings of various thicknesses 
allowed to diffuse for two months at 203 F were 
found to afford as much protection as those without 
the diffusion treatment. Hence, diffusion of zinc on 
storage at high atmospheric temperatures will not 
decrease the protection. No zinc coating other than 
that applied by electroplating was found satisfac- 
tory. Metal sprayed zinc does not adhere unless the 
brass surface is roughened more than can be toler- 
ated, and sherardized coatings are less protective 
than electroplated ones of equal thickness. More- 
over, the sherardizing process requires temperatures 
above those used for stress-relief annealing. 

Under the test conditions where unprotected brass 
specimens break in 5 hours, those coated with 0.0003 
in. of zinc stand up 120 hours; with 0.0006 in., 240 
hours; and with 0.0013 in., 500 hours. Thus, the life 
increases linearly with thickness of zinc coating. 

The electrochemical protection afforded by the 


CONFIDENTIAL 


76 


AMMUNITION 


zinc is noteworthy. Small scratches through the zinc 
do not materially decrease the life, while the life of 
a test specimen with a zinc coating 0.003 in. thick 
and with a bare space i/g in. wide, freed from zinc, 
falls only to 100 hours. A further increase in life 
results when the zinc coating is “Cronak” treated, 
that is, dipped in a solution that produces a thin film 
of slightly soluble chromate on the surface. In the 
presence of atmospheric humidity, this film supplies 
a chemical inhibitor against corrosion. The filming 
does not destroy the electrochemical protection of 
areas scratched or bared after the filming treatment. 
Brass coated with 0.0003 in. of zinc, chromate filmed, 
then scratched to bare brass, will last 175 hours. 

Instead of applying the zinc electroplate to the 
completely formed cartridge case, manufacturing 
would be simplified if the plating could be done at 
an earlier stage. On the basis of preliminary experi- 
ments, plating of fourth draw pieces with 0.0003 in. 
of zinc, with the final anneal converting the zinc 
to an alloy by diffusion into the brass, and the pos- 
sible flaking off of some of the alloy, would still 
result in somewhat reduced, but still very long, life. 
This feature should be studied more completely if 
zinc plating is to be adopted. 

Zinc, or zinc-coated brass, is not appreciably at- 
tacked by various propellent powders, even on stor- 
age at 122 F for a year. A comparative test of a dura- 
tion of 1 year was inconclusive in that the unstress- 
relieved, unplated cases used for comparison with 
plated ones did not themselves show season crack- 
ing in this period of exposure. At any rate, in addi- 
tion to the fact that the zinc-coated cases did not 
crack, neither did they show visible corrosion. 

Since the zinc coatings and coatings with the 
chromate treatment proved effective even when 
scratched, zinc, zinc oxide, and zinc chromate were 
used as pigments in several types of lacquers. The 
lacquer thickness was about 0.0015 in. The testing 
technique was the same as that on the zinc-coated 
specimens. Zinc oxide or zinc chromate alone had 
little effect, but zinc dust (actually a mixture con- 
taining 80 per cent of zinc and 20 per cent of zinc 
oxide) did show considerable protection, and the 
scratched specimens behaved about as well as the un- 
scratched. A variety of other pigments and a mixture 
of 80 per cent zinc dust and 20 per cent of plaster of 
Paris in a urea-formaldehyde vehicle failed to do 
very well when the lacquer was scratched, but zinc 
sulphide in this vehicle (coating 0.001 1 to 0.0012 in. 


thick) showed marked protection. However, it did 
not do so in a phenolic resin vehicle. 

In urea-formaldehyde, bismuth trisulphide or lead 
sulphide was even more effective than zinc sulphide, 
in 0.0010 to 0.0020 in. thickness. However, none of 
the three useful sulphides gave satisfactory perform- 
ance when the pigmented urea-formaldehyde coating 
was less than 0.0010 in. thick. This is three times 
the thickness that can be allowed on cartridge cases. 

Several thin organic coatings, if continuous and 
not scratched, prevent ammonia stress-corrosion. 
Among these are a wax known as Puritan Cartridge 
Coating Compound and an unmodified phenol- 
formaldehyde coating. None of these exert protec- 
tion when scratched through. 

Another possible way of minimizing stress-corro- 
sion would be to put the surface in compression, as 
by shot-blasting, a method known to be effective in 
combating fatigue failures. Slight mechanical work- 
ing by hand burnishing or scratch brushing, as well 
as shot-blasting, in some cases showed minor im- 
provement in life, but much less than is produced 
by a very thin coat of zinc. Since the commercial 
application of shot-peening was considered difficult 
to apply to cartridge cases, particularly to the inte- 
rior, its possibilities were not further followed up in 
this project. It is possible, however, that the applica- 
tion of 150,000 psi in tension in the test method used 
more than neutralized the surface compression 
stresses introduced by shot-peening. 

This project clearly demonstrated the efficacy of 
thin electroplated zinc coatings and the electro- 
chemical protection afforded to scratched areas. The 
results of the work are summarized in the final re- 
ports,’^'^®’^'^^ while the details are covered compre- 
hensively in five progress reports. 

Evaluation and Elimination of Residual Stresses 

Stress-corrosion cracking in cartridge brass is 
avoided if there is no corrosion or if there is no stress. 
The project discussed above related to prevention of 
corrosion. Another project, relating to the evalua- 
tion and elimination of residual stresses, was estab- 
lished at Lehigh University by the Metallurgy Sec- 
tion of former Division B of NDRC. This was Project 
B-220 (OD-25), Residual Stresses in Cold-Drawn 
Non-Ferrous Alloys. 

The distribution of internal stress can be approxi- 
mately ascertained by machining or splitting off 
layers and noting the dimensional changes resulting 


CONFIDENTIAL 


CARTRIDGE BRASS 


77 


from the removal of this material. Another way is 
by use of X-ray diffraction methods which can be 
applied to measure the interplanar spacings between 
atoms in the metallic crystal. In strain-free material 
this spacing has a fixed value. If compressive stress 
is present, the atoms are squeezed together and the 
spacing is smaller. If tensile stress is present, they 
are pulled apart and the spacing is larger. Therefore 
by measuring the spacing in a stressed area and com- 
paring it with the value determined for the normal 
lattice, the existing stress can be evaluated. 

The X-ray measurement can be made accurately 
only on the surface. However, by etching away suc- 
cessive surface layers and determining the surface 
stress each time, the redistribution of stress, resulting 
from removal of material is shown. From this re- 
distribution, the original stress conditions prior to 
etching can be calculated. The method offers pos- 
sibilities of greater precision than can be obtained 
by measuring dimensional changes. 

Extension and refinement of the X-ray method 
applied to measurement of stresses in cartridge cases 
was desired by Frankford Arsenal, and Project B-220 
(OD-25) was set up with these aims in view. 

The production methods used in making cartridge 
cases generally result in compressive stresses at the 
surface. The higher the compressive stress and the 
greater the depth to which compressive stress ex- 
tends, the more the resistance to stress-corrosion 
cracking, which results partially from tensile stress. 
Tensile stress, to balance the surface compressive 
stress, will occur below the surface. When corrosion 
penetrates the surface locally and gets down to mate- 
rial that is under tensile stress, stress-corrosion crack- 
ing will occur. 

X-ray measurements applied to cartridge cases 
processed in different ways can reveal the stress dis- 
tribution at each step and thus point the way toward 
modifications in processing methods which could 
remove or delay the danger of stress-corrosion crack- 
ing. The effect of different methods of pickling, pro- 
ducing rough or smooth surfaces that hold or do 
not hold lubricant in the next draw, die angles of 
the drawing die, etc., were examined. The effect of 
variation in composition (percentage of zinc) and 
of a zinc gradient due to volatilization of zinc from 
the surface had to be taken into account. 

Because of the varying amount of cold work at 
different locations in the case, the varying thick- 
nesses, and the variation of restraint upon the walls. 


which is high at the base and low in the body, the 
stress conditions vary considerably over the length 
of the case, making measurements at several loca- 
tions necessary. The X-ray method examines only 
a small spot and thus is a more selective measure 
than are dimensional measurements. 

The equipment and technique for X-ray measure- 
ment of surface stresses on the outside and inside 
of caliber 0.30 cases are fully described in the reports, 
and the results of many variations in processing upon 
the magnitude and distribution of stresses are 
recorded. 

In general, the method gives useful and illuminat- 
ing results, but in the ammonia-cracking test, body 
cracks occur that could not be predicted by the X-ray 
studies. This anomaly needs further study. Final 
reports^'^'''^^^ have been used on many phases of 
the problem, but the work is being continued under 
a direct contract with the Ordnance Department. 

Effect of Density-Volume Changes Associated 
WITH Phase Changes 

A possible cause for susceptibility to intergranular 
corrosion, as well as for the splitting of cartridge cases 
during forming, might be the initial presence in the 
cake from which the strip is rolled for forming of 
some beta (zinc-rich) phase in the alpha (copper- 
rich) phase. 

The beta phase exists in the center, which is the 
part last to freeze, of most large cakes. It is diffused 
and transformed to the alpha phase by annealing. 
If the annealing is insufficient, however, diffusion 
will not be complete and a laminated structure will 
result revealing ghost or phantom lines where the 
beta phase occurred. The brass may show a finer 
grain along the contact line, and grain size is im- 
portant in the fabrication of brass. 

It was suspected that the transformation might 
leave voids at the original beta location because the 
beta phase is very slightly less dense than the alpha 
phase, that is, it occupies more volume. 

To investigate this problem Project NRC-62 (OD- 
117) was established at the University of Minnesota 
in July 1943. It was shown that (1) the volume 
changes which result from transformation of the beta 
phase to the alpha phase are extremely small and do 
not cause voids, and (2) proper annealing, even of 
cartridge brass with zinc content at the high zinc end 
of the specification, will prevent any trouble that 
might arise from the initial presence of beta.^^^ 


CONFIDENTIAL 


78 


AMMUNITION 


4.4 DRIVING BANDS 

Shortage of copper forced Germany to find substi- 
tutes for copper or gilding metal driving bands. 
Under Project NRC-32, Examination of Enemy 
Materiel discussed in Chapter 8, several German 
driving bands were examined. The first step in cop- 
per conservation was the use of a bimetal band, with 
copper on the outside, soft iron on the inside. In- 
stead of being made as a complete ring, the bimetal 
band was made in sheets, presumably by hot-rolling 
a slab of iron surmounted by a slab of copper. Strip 
of the proper dimensions was cut from the duplex 
sheet and forced into a knurled and undercut groove. 
The ends were so forced together that the joint could 
scarcely be found by visual inspection. Despite this 
joint, the band functioned properly. 

In the duplex band, the iron extends nearly to 
the surface of the projectile; the raised part which 
contacts the lands and grooves of the gun is copper. 
This saves approximately half the copper that would 
be required by a solid copper band. 

The duplex band was used as a first-step conserva- 
tion measure but was later replaced by all-soft-iron 
bands, used only to a limited extent, or, more com- 
monly, by sintered-iron bands. These were formed 
in ring shape from metal powder. This powder was 
derived not from very pure iron, but rather from 
scrap low-carbon steel much like that used by the 
Germans for cartridge cases. The compacted ring 
was lightly sintered, impregnated with oil to prevent 
rusting, and pressed into the undercut, knurled 
groove. After pressing in, it still had some 20 per cent 
porosity, which permits easy deformation. The 
metal-powder bands in place appear very brittle 
when they are being pried off, but they withstand 
the compressive and shear stresses caused by being 
engraved by the lands and grooves in driving the 
projectile. They have become the German standard 
for projectiles up to 150 mm and have replaced the 
duplex copper-iron band. 

It was suspected that the sintered-iron band would 
wear the gun tube more than the copper of the 
duplex band. On the contrary, a captured German 
document, (OTIB 155 D338, August 1, 1943) shows 
curves of increase in the diameter of lands at the be- 
ginning of rifling of a 105-mm light field howitzer 18 
(over 8,000 rounds), with projectiles equipped with 
bimetal and with sintered-iron bands. 

At 5,000 rounds, the land diameter had increased 


0.7 mm with the bimetal band, but only 0.2 mm with 
the sintered-iron band. Increases of 0.8 and 1.0 mm 
at that location are shown in another curve as having 
brought the 105-mm light field howitzers to the ends 
of their useful lives. Extrapolating the first pair of 
curves, it would appear that the use of the bimetal 
band on the projectiles would give the howitzer a 
life of 7,000 to 10,000 rounds, while the sintered-iron 
bands would give double that life. A definite state- 
ment that the life of this howitzer is doubled with 
the sintered-iron band is also made in this document. 
In the course of other comments in this document, 
reference is made to the great pressure exerted by the 
bimetal band. The sintered-iron band is also pre- 
ferred to the bimetal because there is no coppering 
of the bore. The film of iron deposited is so slight 
as to be of no importance. 

From this evidence it would appear that the com- 
plete replacement of copper in the driving band 
by sintered iron might, from the performance point 
of view as well as from that of conservation of copper, 
be more fruitful than partial substitution by the bi- 
metal band. The Army Ordnance Department has 
been experimenting with various sintered, metal- 
powder bands. 

However, the suppliers seem to have sought to 
secure density and freedom from porosity, trying 
to make the product as much like a solid iron band 
as possible, whereas the performance of the German 
band is probably due to its porosity. An inspection 
team in Germany after cessation of hostilities found 
records comparing solid, soft iron bands, which were 
in limited use, with sintered bands, much to the 
advantage of the porous band in regard to barrel 
wear. It was also reported that the iron powder was 
made by grinding up low-carbon steel scrap, rather 
than by electrolysis or by the reduction of the oxide. 
The compositions of German steel cartridge cases 
and powdered iron bands were so similar that it 
appears likely that scrap cartridge cases or trimmings 
from cartridge cases were the raw material. 

However, until the German data on wear with 
the sintered band are confirmed by American tests, 
the duplex band in which the operating face is 
copper seems a logical first step in conservation. 

At the request of the Bureau of Ordnance, Navy 
Department, Project NRC-60 (No-159), Bi-Metallic 
Rotating Bands for Projectiles, was established by 
NDRC at the General Electric Company Research 
Laboratories. The objective of this project was to 


CONFIDENTIAL 


DRIVING BANDS 


79 


investigate methods of producing a satisfactory bond 
between copper and steel by means of alloys and a 
study of the mechanical properties of bimetal driv- 
ing bands for 40-mm naval projectiles. 

German methods of production could not be ap- 
plied, for the instructions from the Bureau of Ord- 
nance were to produce bimetal rings, not strip, in 
order to retain the usual technique of banding. The 
possibility that bimetal tubing, to be cut into bands, 
could be made by centrifugal casting had been ex- 
plored by the U. S. Pipe and Foundry Company 
under Project NRC-26 (discussed in Section 7.2.5 
of this report). It was not found feasible to cast iron 
inside copper owing to the respective melting points, 
although a copper-lined iron tube could have been 
produced.^®^ Other casting methods tried were un- 
satisfactory, so recourse was taken to bonding a 
copper tube to a steel tube placed inside it. 

Various brazing solders were tried, along with 
various methods of heating the nested pair of tubes. 
Zinc was selected as the best bonding agent since 
it alloys with both iron and copper at a relatively 
low temperature. Metal spraying appeared to be the 
best method of applying the zinc. 

SAE 1010 carbon steel tubing 1.715-in. OD, 0.30-in. 
wall, surface ground, was spray-coated with 0.006 in. 
of zinc and slipped inside a 2-in OD, 0.125-in. wall 
copper tube. The composite tube was drawn through 
a single die to 1.846-in. OD, 1.570-in. ID, over a 
plug. This resulted in a composite tube with wall 
thickness of 0.103 in. copper, 0.005 in. zinc, and 
0.130 in. steel. After various methods of heating in 
an attempt to melt the zinc and produce bonding, 
8-in. sections were heated 20 to 25 minutes in an 
electric muffle furnace operating at 1740 F. This pro- 
duced some volatilization of zinc as vapor and did 
not bring about 100 per cent bonding. At least 75 
per cent of the area was bonded and the unbonded 
areas were uniformly distributed. This partial bond 
was appraised as stronger than the grip on the knurl- 
ing of the shell, and hence adequate for the purpose. 
A lot (Lot 1) of 34 shells was provided with bimetal 
bands so made. Banding was performed as usual and 
without trouble. 

To produce more complete bonding, another lot 
(Lot 2) was prepared in the same manner, but 
heated for bonding in a hot press consisting of a pair 
of carbon blocks shaped circumferentially to fit the 
OD of the composite tube. Current was passed 
through the assembly, heating it to 1740 F. After 


about 6 minutes heating, while the tube was hot, 
slight pressure was put upon the outside of the tube, 
the current was cut off, and pressure was maintained 
until the tube was cool. Copper is soft enough at 
1740 F so that a tight bond is obtained. In produc- 
tion, this external pressure probably would be ap- 
plied by hot drawing through a die. Lot 2 contained 
62 shells provided with bimetal bands made by the 
hot press method. 

Lots 1 and 2 were fired by the U. S. Naval Proving 
Ground at Dahlgren. The Dahlgren report stated 
that examination of Lot 1 showed discontinuous 
bond and a possible tendency to strip, while Lot 2 was 
sound, with no indication of deficiency in ductility 
or strength. Apparently, both lots functioned prop- 
erly in the firing tests. 

Since the results obtained with the naval 40-mm 
projectile were so successful, work was done also^®^ 
on the production of driving bands for the naval 3-in. 
projectile and the Army 37-mm projectile. The 
attempts to produce satisfactory driving bands for 
the naval 3-in. projectile by the above method were 
unsuccessful because the hot press equipment used 
for the purpose did not have sufficient electrical capa- 
city to effect rapid heating and to attain the tempera- 
ture required to produce the alloy bond. A lot of 
Army 37-mm driving bands was shipped to Frank- 
ford Arsenal for firing tests. The results of these tests 
have been reported by Frankford Arsenal. 

It was concluded that the process could be used 
to conserve copper. The cost of production would, 
of course, be above that of an all-copper band, so 
that the process would not be economical when 
copper is available.^*^ 

It would be logical to extend this work to bimetal 
strip rather than confine it to bimetal rings, since 
the German experience shows strip bands to be effec- 
tive, and their production would be much simpler. 

A U. S. Naval Technical Mission in Europe con- 
cluded,^®^ on the basis of documents searched and 
interrogation of German personnel, that (1) the 
copper-clad steel band will give almost as good serv- 
ice as a copper band; (2) the sintered-iron band was 
the best substitute for copper bands, although its 
development was not as yet complete; and (3) soft 
iron bands were not so satisfactory as the copper, 
copper-clad steel, or sintered-iron bands, although 
they were a substitute for sintered-iron bands in high- 
velocity and large guns for which the sintered-iron 
band had not proved to be satisfactory. The Germans 


CONFIDENTIAL 


80 


AMMUNITION 


realized that the investigation of the sintered-iron 
band and rifling design was by no means complete. 

In view of the evidence indicating that German 
experience evaluated the porous sintered-iron band 
as the best substitute for solid bands in some types 
of guns, at least on the score of barrel wear, further 


study of driving bands obviously should begin with 
the duplication of porous band and its trail in Ameri- 
can guns. That band seems so good in performance, 
as well as on the score of complete observation of 
copper, that further effort on the duplex band could 
at least be deferred until test results are available. 


Chapter 5 

METALS FOR HIGH -TEMPERATURE SERVICE 


5 1 GAS TURBINES AND 

TURBOSUPERCHARGERS 

E arly in 1942, the Bureau of Ships, Navy Depart- 
ment, indicated an urgent need for better heat- 
resisting alloys than those then available for use in 
the construction of gas turbines for ship propulsion. 
It was stated that alloys were needed for use in fabri- 
cation of turbine buckets which would show a creep 
rate not in excess of 0.00001 per cent per hour at 
1500 F and stresses of 7,000 psi. 

The Office of the Coordinator of Research and 
Development, Navy Department, requested NDRC 
to institute a research program to evaluate the known 
alloys and to develop and test new and improved 
alloys for the desired service requirements. Project 
NRC-8 (N-102), Heat-Resisting Metals for Gas Tur- 
bine Parts, and Project NRC-41 (N-102), Heat Treat- 
ment of High-Temperature Alloys, were established 
to carry out this research program. 

Long-time high-temperature tests require special 
equipment and special techniques possessed by only 
a few research laboratories which have specialized 
in this type of testing and have gained the experi- 
ence required to produce reliable results. Several 
government laboratories and some dozen other lab- 
oratories, the latter heretofore occupied with the 
high-temperature problems of industry, possessed 
this experience and test equipment. The facilities 
of these laboratories were largely diverted from 
their previous activities to this heat-resisting alloy 
problem.^ 

Most of these laboratories put practically all of 
their facilities and personnel for high-temperature 

a Under OSRD contracts, laboratories of the following organ- 
izations were engaged to work cooperatively on the project: 
American Brake Shoe Company, Battelle Memorial Institute, 
Climax Molybdenum Company, Crane Company, Federal 
Shipbuilding and Drydock Company (United States Steel Cor- 
poration Research Laboratories) , Lunkenheimer Company, 
The Massachusetts Institute of Technology, Midvale Company, 
National Bureau of Standards, University of Michigan, 
Vanadium Corporation of America, and Westinghouse Elec- 
tric and Manufacturing Company. 

Additional data and cooperation were supplied by the fol- 
lowing organizations not under OSRD contract: Allegheny 
Liidlum Steel Corporation, Crucible Steel Company, General 
Electric Company, Haynes Stellite Company, International 
Nickel Company, Inc., Union Carbide and Carbon Company, 
Universal Cyclops Steel Corporation, and U. S. Naval Engi- 
neering Experiment Station. 


research on this work directed by the War Metal- 
lurgy Committee. 

At the same time, research sponsored by the Na- 
tional Advisory Committee for Aeronautics and 
conducted at the University of Michigan was deter- 
mining the tensile and stress-rupture properties at 
1200 and 1350 F of many heat-resisting alloys in 
order to evaluate their usefulness for turbosuper- 
charger and gas turbine wheels. 

In the NRDC program, the temperature of inter- 
est was stated initially to be 1500 F, but the scope 
of the research was broadened to cover long-time 
creep testing at the lower temperature of 1350 F 
and all types of tests at 1600 F. Later tests were run 
on the better alloys at 2000 F. 

In the NACA program, all types of tests were run 
at 1200 F, stress-rupture tests were made at 1350 F, 
and, more recently, some of the promising alloys 
were tested at 1700 and 1800 F. 

The two concurrent research programs sponsored 
by NACA and NRDC were carefully coordinated 
to eliminate duplication of effort and to provide all 
types of test data over the entire temperature range 
from 1200 to 2000 F. 

The requirements of the Bureau of Ships, Navy 
Department, for alloys for long-time service required 
final evaluation of the properties of the most prom- 
ising alloys in long-time tests, or creep tests of at 
least 2,000 hours’ duration. However, because of 
limited test equipment and manpower, it was neces- 
sary to compare the available alloys and to evaluate 
new alloys first by stress-rupture tests which deter- 
mine the stresses required to produce rupture in 
given shorter time periods such as 10, 100, and 1,000 
hours. 

Activities of the Bureau of Aeronautics, Navy De- 
partment, developed the need for alloys suitable for 
use at higher stresses than 7,000 psi at 1500 F, but 
with shorter requirements for useful life. In the 
stress-rupture tests used for developments of alloys 
of the desired low creep rate, considerable data of 
direct value for this purpose were obtained. Only 
those alloys indicated as promising were subjected 
to long-time creep testing. 

Tests were made on 96 heat-resisting alloys. These 
alloys were principally of Cr-Ni-Fe, Co-Cr, Cr-Ni-Co, 


81 


82 


METALS FOR HIGH -TEMPERATURE SERVICE 


and Cr-Ni-Co-Fe bases. Some were made available 
in wrought form while others were supplied in the 
form of precision-cast test pieces. Tests were also 
made on material cut from large forged disks of four 
heat-resisting alloys. Alloys for high-temperature 
service contain a considerable amount of chromium 
to confer resistance to oxidation, and a considerable 
amount of nickel or cobalt or both to render the 
alloy austenitic, since austenitic alloys far surpass 
ordinary ferritic steels in high-temperature strength. 
Rather generous additions of carbide-forming ele- 
ments, such as molybdenum, tungsten, columbium, 
titanium, and tantalum, either singly or in combina- 
tion, whose carbides can be separated out by a pre- 
cipitation-hardening type of heat treatment, further 
raise the high-temperature strength. For each of 
these alloys it was necessary to work out the opti- 
mum heat treatment. The required time and tem- 
perature for solution of the carbides, the cooling 
rate from the solution temperature, and the reheat- 
ing or aging time and temperature all had to be 
determined experimentally. Detailed heat treat- 
ment experiments were carried out on seven alloys 
under Project NRC-41, Heat Treatment of High 
Temperature Alloys.^®®’^®^ 

In addition to the stress-rupture and creep prop- 
erties determined for the various alloys, impact 
resistance and short-time tensile properties were 
determined at selected elevated temperatures. For 
determination of stability of the alloys, hardness, 
impact resistance, and tensile strength were deter- 
mined on material after long-time testing in stress- 
rupture or creep tests. 

The numerous tables, figures, and graphs in the 
various progress reports show in detail the proper- 
ties of all the alloys tested.i9o-i93 por the stress-rup- 
ture and creep tests, the actual time-deformation 
curves were presented to facilitate comparisons be- 
tween the alloys by designing engineers on bases 
other than those arbitrarily chosen by the War 
Metallurgy Committee Research Supervisor for the 
program. The order of superiority of the alloys is 
not the same at different temperatures; moreover, 
at some temperatures forgings appear better than 
castings, while at others, the reverse is true. Extra- 
polations are dangerous, actual tests or evaluation of 
alloys under service operating conditions being 
desirable. 

At the start of this work in early 1942, the War 
Metallurgy Committee conducted a survey of the 


current data on alloys suitable for high tempera- 
ture service in gas turbine and supercharger parts. 
This survey. Project SP-5, was made in collabora- 
tion with the Naval Engineering Experiment Sta- 
tion and NACA.i^^ It was found that only limited 
data were available on about six heat-resisting alloys 
indicative of promise for gas turbine and turbosuper- 
charger service. Of these alloys, two showed a stress 
for 1,000-hour rupture and 1500 F at 9,000 and 

11.000 psi, while two others were somewhat stronger 
and showed about 15,000 psi for rupture in 1,000 
hours. Creep-test data were available at 1500 F for 
only one alloy and this gave a creep rate of 0.00001 
per cent per hour at about 5,000 psi, whereas the 
Navy Department desired a material with this creep 
rate at 7,000 psi or higher. 

At the termination of the NDRC work, nine cast 
alloys were known with 1,000-hour rupture at 1500 
F in excess of 20,000 psi and up to 26,000 psi. Six 
forged alloys were known with 1,000-hour rupture 
at 1500 F between 15,000 and 18,500 psi. 

At 1600 F, the cast cobalt-base alloys were definite- 
ly superior to the forged alloys with rupture in 1,000 
hours between 14,500 and 17,500 psi as compared 
with 8,000 to 10,000 psi for the best forged alloys. 

At 2000 F, the best cast cobalt-base alloys showed 
rupture in 100 hours between 4,000 and 5,000 psi. 

In the creep tests, at 1500 F cast alloy X-40 showed 
the best creep resistance with a stress of 11,000 to 

12.000 psi indicated for a creep rate of 0.00001 per 
cent per hour. All the other cobalt-base alloys, with 
the exception of Vitallium, are indicated to be above 

8.000 psi for this rate of creep. Four of the forged 
alloys showed creep rates of 0.00001 per cent per 
hour at 7,000 psi or higher, with one alloy indicated 
between 10,000 and 11,000 psi. 

Creep tests were made at 1350 F on those alloys 
showing promising properties at 1500 F. The better 
forged alloys, as a group, had better creep resist- 
ance at 1350 F than did the cast alloys, a relationship 
reversed from that at 1500 F. 

Creep tests at 1600 F indicated that several of 
the forged and cast alloys met at this temperature 
the requirements which had been set as the original 
goal at 1500 F. 

For four of the forged alloys which tests on bar 
stock indicated as promising for use as gas turbine 
rotors, large forged disks were obtained and high- 
temperature tests over the temperature range 1200 
to 1500 F are in progress jointly between NACA and 


CONFIDENTIAL 


GAS TURBINES AND TURBOSUPERCHARGERS 


83 


the Navy Department on material cut from various 
locations in the disks. 

It is certainly to be expected that among the pos- 
sible combinations of precipitation-hardening ele- 
ments in an austenitic matrix, new elements or com- 
binations, some as yet untried, may be materially 
superior to those so far evaluated. 

The Vanadium Corporation of America, one of 
the contracting laboratories on Project NRC-8, melt- 
ed and cast a large number of Cr-Ni-Co and Cr-Ni- 
Co-Fe base alloys with considerably higher molyb- 
denum or tungsten additions than the majority of 
the alloys tested in the balance of the program. Pre- 
liminary appraisals of the effects of these additions 
were made by means of high-temperature hardness 
determinations. In these alloys, the effects of addi- 
tions of other elements, including vanadium, boron, 
beryllium, titanium, and aluminum on the hot hard- 
ness were also determined. Some of these alloys 
possess very high hardness at 1500 F, some as high 
as 400 Brinell. Stress-rupture properties at 1600 F 
have been determined on a few of these alloys. 
Ductilities upon rupture tend to be low. Testing 
was restricted by lack of facilities, but at least four 
of the alloys show properties at 1600 F superior 
to those of the best cast cobalt-base alloy. It is ob- 
vious that there is opportunity for still further im- 
provement in this family of alloys, improvements 
that might be of great portent to the gas turbine. 
To date, the effects of carbon content, heat treat- 
ment, and melting practice (deoxidation and grain 
size) on strength and ductility are not known.^^^ 

However, attention has not been confined in the 
heat-resisting alloy program to the families of alloys 
previously discussed. Other families, whose process- 
ing and fabrication offer such difficulties that past 
investigators have done little or no serious work on 
them and whose properties were entirely uncharted, 
might be so much better that the difficult job of 
working out their fabrication problems might be 
well worth tackling. The value of super high-tem- 
perature alloys in gas turbine service is so great 
that cost of raw material and processing, which would 
be prohibitive for less important uses, is no barrier. 

With these aspects in mind, the Climax Molybde- 
num Company, one of the contracting laboratories 
on Project NRC-8, surveyed the field of possible new 
alloy systems. Various binary and ternary alloy sys- 
tems formed using elements with melting points 
considerably in excess of the presently used alloys 


were investigated, including chromium, molybde- 
num, tungsten, columbium, platinum, thorium, 
vanadium, and zirconium. Considering availability 
and properties, the most interesting of these refrac- 
tory metals is chromium. An outstanding presenta- 
tion of the properties of the alloys of chromium 
and the methods of melting, purifying and shaping 
of the alloys has been made by the Climax Molyb- 
denum Company in two reports.^^*^-^^^ 

The alloys having the best combination of strength 
and ductility at 1600 F were found in the composi- 
tion range from 60% Cr, 35% Fe, 5% Mo to 60% Cr, 
15% Fe, 25% Mo. Alloys with 60% Cr and between 
15 and 25% Mo, balance iron, show rupture times 
at 1600 F and 30,000 psi as long as those of the best 
cobalt-base alloys at 20,000 psi. Heat-treatment ex- 
periments indicate still greater promise for these 
alloys, and the study of these chromium-base alloys 
containing iron and molybdenum is being contin- 
ued at Battelle Memorial Institute under the spon- 
sorship of the Office of Research and Invention, Navy 
Department. 

Service tests under actual gas turbine operating 
conditions have been arranged for most of the prom- 
ising bucket alloys whose properties were deter- 
mined. Some are under test at the U. S. Naval Engi- 
neering Experiment Station in a General Electric 
turbosupercharger using hot gas produced from 
combustion of Navy Bunker C fuel oil. Other alloys, 
including alloys from the Vanadium Corporation 
and the Climax Molybdenum Company work, have 
been installed and are being tested in a Westing- 
house aircraft gas-turbine jet-propulsion engine. 
These service tests are still in progress, so compari- 
sons between the alloys which possess somewhat dif- 
ferent strengths and ductilities are not yet available. 

In some types of high-temperature service, notably 
those with rotating parts, there is likelihood of vibra- 
tion which may set up extraordinary stresses so that 
the behavior of the alloys in fatigue and notch fatigue 
at operating temperatures should be known. From 
this point of view, the ability of the material itself 
to damp out vibrations at operating temperature is 
also of interest. The Westinghouse Electric and 
Manufacturing Company has made available a large 
quantity of fatigue data determined in their own 
laboratory and these data have been reported in 
the progress reports on Project NRC-8. Some high- 
temperature fatigue work was begun and will be 
continued under a Navy Department contract. As 


CONFIDENTIAL 


84 


METALS FOR HIGH -TEMPERATURE SERVICE 


would be expected, alloys which show outstanding 
resistance to deformation under stress at high tem- 
peratures, also tend to have low damping capacity, 
and vibration apparently must be avoided by means 
other than by choice of material. Data on the damp- 
ing capacity of some of the high-temperature alloys 
were collected and compiled.!^® (See also Section 5.3 
of this report.) 

Assembly of buckets on gas turbine rotors is facili- 
tated if welding can be used. In June 1944 the War 
Metallurgy Committee Project Committee for the 
heat-resisting alloy program reported that a number 
of turbine fabricators were experiencing welding 
problems and that there was a serious need for weld- 
ability data on the newly developed heat-resisting 
alloys. Three types of weld joint defects were re- 
ported to occur in welded wheels as follows: (1) 
notch extensions or a form of cracking which initiates 
at the junctions between buckets on the outer edge 
of the weld metal and propagates radially across the 
welded joint eventually reaching proportions en- 
dangering the strength of the wheel; (2) weld metal 
bead cracking in the form of longitudinal cracking 
in the center of the deposited weld bead and also 
in the form of scattered intergranular fissures; and 
(3) under bead cracking in the fusion zone and heat- 
affected zone in heavier section buckets of jet unit 
and gas turbine wheels. In order to investigate these 
problems and to evaluate the relative weldability 
of a series of selected alloys. Project NRC-90 (N-102), 
Weldability of Heat-Resisting Alloys, was established 
in the laboratories of the Rustless Iron and Steel 
Corporation in July 1944. 

Simple weld tests were investigated in an attempt 
to produce the defects encountered in welding heat- 
resisting alloys by the submerged-melt and manual- 
arc processes. A wheel-and-bucket design test was 
ultimately developed and, of 80 such tests planned, 
about one-third had been completed by October 
1945 when the NDRC project was terminated.i*-^^ 
Sufficient work completed to show that wide varia- 
tions exist in the susceptibility of different heat- 
resisting alloys to the development of welding 
defects. This welding work is being continued by the 
Rustless Iron and Steel Corporation under a Navy 
Department contract with Battelle Memorial Insti- 
tute. 

The results obtained in the heat-resisting alloy 
program have indicated that improvements made in 
the alloys now commercially available exceed the 


requirements originally set by the Navy Depart- 
ment, and still further improvements are to be 
expected, particularly in the new alloy systems inves- 
tigated. The data of the program were presented in 
comprehensive reports,^®*'^^^’!^^’-^^’^®^ An index-^^^ 
of the Division 18 reports on heat-resistant alloys 
was prepared by the Research Information Division 
of the War Metallurgy Committee. This index gives 
a subject index of the various reports issued on each, 
a numerical list of reports with a brief abstract of 
the contents of each, and a subject-index of the re- 
ports. It lists also the alloys investigated. Several 
special reports not specifically mentioned in the fore- 
going discussion also were issued as follows: Survey 
of Data on Alloys Developed for Turbosupercharger 
and Gas Turbine Applications,^^- Machining Data 
on Heat-Resisting Alloys,-^''- Metallurgical Investi- 
gation of a I.arge Forged Disc of Low-Carbon N-155 
Alloy. The last-named joint NDRC-NACA re- 
port brought together the data of the NDRC and 
NACA projects on the subject. At the specific re- 
quest of the Armed Services, these reports were dis- 
tributed to their contractors who were concerned 
with the development and use of heat-resisting alloys. 
The data presented have had wide use by designing 
engineers in specifying designs and materials for 
improved gas turbine power plants for marine and 
aircraft use now under construction. 

Research on heat-resisting alloys of the more 
common Cr-Ni-Fe and Cr-Ni-Co-Fe types was car- 
ried out by the American Brake Shoe Company un- 
der Correlation Project NRC-84A, Heat Resistant 
Alloys for Ordnance Materiel and Aircraft and 
Naval Engine Parts. This program, which was 
financed by the American Brake Shoe Company and 
conducted under the general supervision of the War 
Metallurgy Committee, covered comprehensive 
studies of alloys of the 21% Cr, 9% Ni type as sub- 
stitutes in applications below 1600 F for the widely 
used 26% Cr, 12% Ni type.^os The effects of cobalt 
and nickel in two groups of 26% Cr alloys, one group 
essentially non-ferrous and the other containing 50 
per cent of iron also were investigated.-®^ 

The cooperation of the alloy producers, the gas 
turbine contractors, and the contracting research 
laboratories in the prosecution of the work under 
the NDRC heat-resisting alloy program was out- 
standing and is a shining example of the willingness 
and ability of industry to cooperate in solving mu- 
tual problems. 


CONFIDENTIAL 


ROCKETS AND JET PROPULSION DEVICES 


85 


5 2 ROCKETS AND JET PROPULSION 
DEVICES 

The Special OSRD Committee on Jet Propulsion, 
in its report dated March 20, 1944, recommended 
that those engaged in the development of rocket 
motors for solid fuels obtain the aid and advice of 
Division 1, NDRC, and the War Metallurgy Com- 
mittee (Division 18, NDRC) on materials for nozzle 
construction. 

Project NRC-88 (AC-75), Metal and Ceramic 
Materials for Jet Propulsion Devices, was established 
at Battelle Memorial Institute to provide advice and 
assistance to the Armed Services, their contractors, 
and other NDRC divisions engaged in the develop- 
ment of jet propulsion devices in matters concerning 
materials of construction for both solid-fuel and 
liquid-fuel rocket motors. 

For this work, in addition to the facilities of Bat- 
telle Memorial Institute, cooperation and assistance 
was obtained from Division 1, NDRC, from metal 
and alloy producers, and from commercial producers 
of ceramic shapes. Assistance on material problems 
was supplied to Allegheny Ballistics Laboratory, 
Division 3, NDRC; Explosives Research Laboratory, 
Division 8, NDRC; California Institute of Tech- 
nology; Bureau of Aeronautics, Navy Department; 
and the Aerojet Engineering Corporation. 

Because of the successful application of chromium 
plate in machine gun liners by Division 1, NDRC, 
similar chromium plates were tried as protective and 
erosion-resistant coatings in rocket nozzles. In noz- 
zles of liquid-fuel units burning mixed acid and ani- 
line, chromium-plated coatings gave very satisfactory 
service. In one trial, a copper nozzle plated with 
0.009 in. of soft low-contraction chromium was 
subjected to 14 firings totaling 79i/4 minutes and 
was still in a satisfactory condition. The use of chro- 
mium-plated nozzles in solid-fuel units was not so 
successful. Blistering and cracking of the plated coat- 
ings occurred, even though suitable adhesion of the 
plate was obtained in most cases. 

Many firing trials were made in solid-fuel units on 
nozzles coated with tantalum, molybdenum, and 
tungsten by vapor phase methods by Battelle Memo- 
rial Institute and by Bell Telephone Laboratories, 
a contractor of Division 1, NDRC. While it was indi- 
cated that these metals possess usable corrosion and 
erosion resistance, satisfactorily consistent ductility 
and adhesion of the coatings to the metal comprising 


the nozzle were not obtained. 

Firing trials on nozzle inserts of pure chromium 
and high-chromium Cr-Mo-Fe alloys, prepared by 
the Climax Molybdenum Company, showed these 
materials to be of considerable promise in that ero- 
sion was practically nil. Further trials of these ma- 
terials seem warranted and desirable. 

Ceramic nozzles of alumina, zirconium silicate, 
and beryllia were prepared by Battelle Memorial 
Institute, and ceramic nozzles of commercial and 
pure refractories of the alumina and silicon carbide 
types were prepared by the Norton Company and the 
Carborundum Company. Several additional com- 
mercial ceramic nozzles were supplied by the General 
Electric Company. In firing tests, all of these ceramic 
nozzles were cracked, probably as a result of lack of 
the necessary heat-shock resistance. None of the 
ceramic nozzles, except for beryllia, were found to be 
erosion resistant, and considerable roughening of the 
surface and spalling was observed. 

Tungsten carbide and boron carbide nozzle inserts 
were tested. Both of these materials, on limited trials, 
appear to show satisfactory erosion resistance, but 
nozzles of both materials were cracked. This cracking 
may be the result of stresses set up by heating and 
cooling of the steel holders in which the nozzle inserts 
were mounted, rather than lack of heat-shock resis- 
tance. These materials, particularly the boron car- 
bide, deserve further study for applications requiring 
nozzles of exceptional performance. It should be 
noted that fabrication of the ceramic or carbide noz- 
zles in a number of pieces divided along the nozzle 
longitudinal axis might relieve the stresses set up 
sufficiently to prevent additional cracking. The Aero- 
jet Engineering Corporation was supplied ceramic 
nozzles for test by the Norton Company, but no 
report of their performance has been received. 

Assistance on material problems to the Bureau of 
Aeronautics, Navy Department, included chromium 
plating of a stainless-steel nozzle, and chromium 
plating of a pump shaft, both used in an acid-aniline 
motor. The chromium-plated nozzle sustained no 
damage in nineteen runs totaling 23 minutes using 
jet velocities up to 6,900 fps with chamber pressures 
between 300 and 550 psi absolute. Considerable work 
was under way for the Bureau of Aeronautics to find 
materials suitable for bearings, sealing rings, adhe- 
sives, and other component parts for the acid pump 
used in this motor, but the work was incomplete 
when the project was terminated in accordance with 


CONFIDENTIAL 


86 


METALS FOR HIGH -TEMPERATURE SERVICE 


the demobilization schedule of NDRC. 

Failures of reed springs operating in the tempera- 
ture range 900 to 1000 F used in buzz bombs led to 
a request for assistance by the Aerojet Engineering 
Corporation. The failures were apparently fatigue 
failures. Data presented in the final report on the 
heat-resisting alloy program^^'"^ indicate which mate- 
rials have outstanding elevated-temperature fatigue 
resistance. Strip 0.010-in. thick of three of the most 
promising alloys (Battelle 8-J, Hastelloy B, and In- 
conel X) was fabricated into reed springs and heat 
treated to produce maximum spring and fatigue 
properties for service at 900 to 1000 F. These reed 
springs were submitted to the Aerojet Engineering 
Corporation for trial, but reports on their perform- 
ance are not as yet available. 

Some of the materials tried in the various firings 
and service applications noted above were sufficiently 
promising to warrant further trials and consideration 
in rocket development work.^o^ Multipiece ceramic 
nozzles, boron carbide nozzles, and nozzles of melted 
and cast pure chromium and chromium-base alloys 
deserve further study for these applications. 


5 3 RESEARCH NEEDS IN THE FIELD OF 
HEAT-RESISTING ALLOYS 

The NACA Committee on Materials Research Co- 
ordination compiled an index of the research proj- 
ects on heat-resisting alloys carried on during World 
War II. During the committee’s discussions of the 
adequacy of the research programs carried out by the 
Armed Forces, NACA, and NDRC, the need for a 
compilation of the properties of sheet materials for 
high-temperature service and a bibliography on the 
damping of metals was emphasized. At the commit- 
tee’s request, the War Metallurgy Committee estab- 
lished and carried out two surveys: Survey Project 
SP-31, Properties of Sheet Materials for High-Tem- 
perature Service, and Survey Project SP-33, Bibliog- 
raphy on the Damping of Metals. The report on 
SP -31 206 covers the properties of materials used in 
fabricating jet engine combustion chambers, ducts, 
exhaust collector rings, etc., while that on SP-332^' 
covers test methods as well as data on the damping 
of metals. 


CONFIDENTIAL 


Chapter 6 

WELDING 


6 1 ARMOR AND ORDNANCE WELDING 

611 Introduction 

E arly in World War II the decision was reached 
to make use of welding as a principal method of 
fabricating much of the vast quantity of material 
needed in the armament program. Attention was im- 
mediately drawn to the problems involved in welding 
metals, which in many cases possessed different char- 
acteristics from those in common use before the war. 
Difficulties encountered by fabricators, particularly 
in the field of armor and alloy steel welding, soon 
made it apparent that a coordinated research effort 
to provide urgently needed information was essen- 
tial to the maintenance of planned production. 

At the suggestion of the Office of the Chief of 
Ordnance, several NDRC projects were established 
with the expectation that the resulting information 
would be of immediate value. Among the most ur- 
gent early problems requiring attention were an eval- 
uation of the relative weldability of rolled homoge- 
neous armor, the development of an armor welding 
electrode which when deposited would exhibit bal- 
listic properties equivalent to rolled homogeneous 
armor, a study of procedures for welding face-hard- 
ened plate, and the development of a satisfactory 
substitute electrode containing the lowest practical 
amount of strategic alloy elements to replace the 
25% Cr, 20% Ni type commonly used for alloy steels 
prior to the war. Less urgent problems included a 
study of the fundamental factors affecting the weld- 
ability of steels, the development of spot welding 
techniques for light armor, a study of methods for 
stress-relieving ordnance steels with special regard 
to machining stability and an investigation of the 
flash welding of aircraft steels. Associated studies 
were initiated as warranted, and other urgent prob- 
lems, such as the repair welding of cast armor, were 
investigated as the war progressed. 

Surveys both of literature and of industrial prac- 
tice were conducted in the fields of armor welding 
and aluminum alloy flash welding preliminary to 
the establishment of research programs on various 
aspects of these subjects. 


Throughout the war considerable aid was fur- 
nished by members of the staff of the War Metal- 
lurgy Committee to the fabricators of ordnance 
equipment in the form of field service and consul- 
tation on special problems that developed in the 
production of certain combat equipment. 

® Armor and Alloy Steel Welding 

In order to determine the research needs in the field 
of armor and alloy steel welding, in July 1941 the 
Metallurgy Section of the former Division B of 
NDRC established a project to survey the literature 
and industrial practice. This survey was conducted 
by Ohio State University under Project B-150, Re- 
search Needs in the Field of Welding and Summary 
of Existing Knowledge on Welding Practice, and re- 
sulted in five comprehensive reports covering the 
research needs,-®® the then current industrial prac- 
tices and procedures for the welding of armor,2o® 
available data on precipitation-hardening alloys 
used in armor welding (OD-36-2, OD-36-3),-i® data 
on the dilation characteristics of alloy steels used in 
ordnance (OD-37-1, OD-37-2) and their significance 
in welding,-^^ and the evaluation and relief of re- 
sidual stresses in welded ordnance structures (OD- 
34-2, OD-34-l).2i2 

This survey disclosed that little information was 
available in this field and that industrial knowledge 
had not progressed to the point where standardized 
procedures were common from one plant to another. 
Each fabricator had experienced difficulties which 
were considered only in the light of the information 
and facilities available, and no unified effort had 
been directed toward the solution of the many basic 
problems involved. 

Since armor plate compositions are not greatly 
different from certain classes of alloy steel in com- 
mon use, the problem of weldability was not en- 
tirely new and considerable use of past information 
and methods of attack was employed in its solution. 
The problem of welding armor plate involves two 
broad aspects. These are, first, the production of 
sound, crack-free welds usually under conditions in- 


CONFIDENTIAL 


87 


88 


WELDING 


volving high restraint, and, second, the subsequent 
performance of the weldment in service. Since the 
service requirements for welded armor plate obvi- 
ously include ability to withstand ballistic impact, it 
was necessary to establish an arbitrary test early in 
the war in the hope that satisfactory performance 
under this test would insure satisfactory service. 

The procedure finally adopted for evaluating the 
quality of welded armor involved the assembling of 
four pieces of armor in such a manner that the 
welded joints form the letter “H” on the completed 
plate. The test consists of subjecting alternate leg 
welds of the H plate to the impact of special pro- 
jectiles which are primarily designed to evaluate the 
shock properties of the weldment. Details of the H 
plate test for various thicknesses of welded armor 
are to be found in Army Ordnance specifications on 
this subject. 

Since the inability of either the armor or weld to 
withstand shock in extreme cases may result in com- 
plete disintegration of a combat vehicle, it was ap- 
parent that equipment subjected to ballistic attack 
with overmatching projectiles must be designed pri- 
marily to resist shock loading, with penetration re- 
sistance of secondary importance. Therefore, early 
production of armor weldments was accomplished 
with the use of austenitic electrodes which exhib- 
ited reasonably satisfactory shock-resisting proper- 
ties with a fair degree of consistency. It also appeared 
that the use of austenitic electrodes in production 
could be satisfactorily controlled. As a result, most 
fabricators evolved successful procedures for welding 
armor using austenitic electrodes, first of the 25% 
Cr, 20% Ni type, and later as the result of alloy 
conservation, of the modified 20% Cr, 10% Ni type. 

It was felt that research effort in the field of eval- 
uating the weldability of commercial armor should 
be devoted to a study of methods of obtaining weld- 
ments with better shock properties than were being 
produced, and also, because of the disadvantages 
associated with austenitic welding and the need for 
conserving strategic alloying materials, to place in- 
creased emphasis on the development and use of 
ferritic electrodes. In addition, there was an urgent 
demand for an investigation to determine the causes 
of first pass cracking in austenitic 20% Cr, 10% Ni 
electrodes. 

Accordingly three research projects were initiated 
and established in the spring of 1942: Project NRC-1 
(OD-82), Weldability of Commercial Armor Plate, 


at the United States Steel Corporation Research 
Laboratories; Project NRC-2 (OD-36-2), Develop- 
ment of Ferritic Armor Welding Electrodes, at the 
Combustion Engineering Company; and NRC-2R, 
Development of Armor Welding Electrodes, at the 
Rustless Iron and Steel Corporation. 

Development of Armor Welding Methods and 
Ferritic Armor Welding Electrodes 

The primary objective of Project NRC-1, Weld- 
ability of Commercial Armor Plate, was not to find 
a method for welding armor, but rather to develop 
better methods than were in current use and to de- 
termine the causes of the erratic shock performance 
of identical weldments. Initial work included the 
preparation and subsequent ballistic testing of H 
plates fabricated using ferritic electrodes and differ- 
ent welding procedures. It should be noted that the 
assembly of an H plate involves the deposition of 
weld metal under high restraint, which enables an 
evaluation to be made of the combined effect of pro- 
cedure, armor composition, and electrode on the 
ability to produce sound, crack-free joints, and pro- 
vides direct information on shock performance when 
tested ballistically. Other primary functions of this 
project were the post-ballistic examination of weld- 
ments, such as H plates, to determine the funda- 
mental causes for failure and to develop and inves- 
tigate the suitability of laboratory tests for the pre- 
diction of ballistic properties. A detailed statement 
of the objectives of the project, together with an out- 
line of the proposed H plate program and prelimi- 
nary test results, is contained in an early progress 
report.2i-^ 

Coincidental with the establishment of Project 
NRC-1 on the evaluation of the weldability of com- 
mercial armor, work was initiated on the ferritic 
electrode development phase of the armor plate 
weldability problem under Project NRC-2. The fer- 
ritic electrode development program was doubly 
important at the time because of the need for con- 
servation of strategic alloys, such as nickel, chro- 
mium, and molybdenum, and because of disadvan- 
tages associated with the use of austenitic electrodes. 
Besides the first pass cracking difficulty mentioned 
previously, these disadvantages include shock prop- 
erties inferior to prime armor, slow deposition rates 
which tend to decrease rates of production, the great 
difficulty of removing austenitic deposits during re- 
pairing, and the necessity for employing wide joints 


CONI IDEN 1 lAL 


ARMOR AND ORDNANCE WELDING 


89 


to avoid failures resulting from localized deforma- 
tion and rupture in the low-yield weld metal during 
ballistic attack, a factor which also tends to slow 
production. 

Originally, it had been intended to treat this par- 
ticular aspect of the armor welding program more or 
less separately, but overlapping with the more direct 
weldability studies was unavoidable, since the in- 
vestigation of electrodes could not be accomplished 
without simultaneously considering all the variables 
inherent in the welding of armor. Early work on 
both projects was therefore closely integrated. The 
progress reports-^^^ -i® complement one another, and 
the final reports-^" -^® summarize briefly the work 
done and the results obtained. 

In the course of the investigations referred to 
above, a considerable number of tests were con- 
ducted on H plate fabricated with ferritic electrodes. 
The majority of these early plates failed by a wide 
margin to pass the arbitrary shock requirements es- 
tablished for austenitic weldments. Analysis of the 
results of these tests tentatively attributed failures to 
several factors, the most important of which were as 
follows: 

1. High residual stresses in and near the welds. 

2. Microcracks not detectable by radiographic ex- 
amination. 

3. Excessively high yield strength of the weld 
metal. 

Subsequent research, however, demonstrated the 
fallacy of these early conclusions. 

With this information available, additional stud- 
ies involving the influence of thermal stress relief 
on the performance of welded armor were initiated. 
An investigation of the residual stress pattern in a 
typical H plate was made which showed that high 
residual stresses approaching the yield strength of 
the weld metal are present in completed H plates.^^^ 
To determine the effect of thermal stress relief treat- 
ments on the hardness of commercial rolled homo- 
geneous armor, a study was made which demon- 
strated that the hardness of five types of rolled ar- 
mor is reduced for treatment temperatures above 
1100 F .“0 Since reductions in hardness lower the 
ballistic penetration resistance and may adversely 
affect toughness, thermal stress relief treatments can- 
not be considered desirable. Practical difficulties en- 
countered in stress relieving large armor weldments 
are of course obvious. 

Extensive studies to determine the magnitude and 


distribution of residual stresses in the longitudinal, 
transverse, and thickness direction in welded plates 
were made at the Massachusetts Institute of Tech- 
nology under Project NRC-53 (OD-106), Effect of 
Locked-Up Stresses on Ballistic Performance of 
Welded Armor. An analysis of the effect of residual 
stresses on ballistic shock performance, as measured 
by a direct explosion test, indicated that the residual 
stress pattern has but minor influence on the shock 
resistance of weldments and that the major cause of 
failure involves purely metallurgical factors.221-223 
Subsequent tests of H plates confirmed these conclu- 
sions. 

Further investigation of commercial and experi- 
mental ferritic electrodes under Project NRC-2 at 
the Combustion Engineering Company, using bead- 
crack sensitivity and restrained joint tests, estab- 
lished the fact that these tests afforded practical 
methods for comparing electrode cracking tenden- 
cies. With these tests and the cooperation of the arc 
welding electrode industry, a large number of com- 
mercially available ferritic electrodes were screened 
to determine their suitability for armor welding ap- 
plications. The results of this early study provided 
sufficient data to eliminate all low-tensile ferritic 
electrodes from further consideration and to con- 
centrate attention on a few high-tensile electrodes-^"* 

After the first few restrained joint tests, the results 
obtained with a Mn-Mo-Si electrode with a lime-type 
coating were so favorable in comparison with the 
other high-tensile ferritic electrodes that all efforts 
were turned toward improving and investigating 
this type of electrode termed the NRC-2A electrode. 
It had been noted during the bead-crack sensitivity 
work that cracking consistently occurred in the heat- 
affected base metal of current armor compositions 
whenever ferritic electrodes of the conventional type 
were used without preheat. The extent of cracking 
varied with both the electrode and the type of armor, 
and high preheat was known to eliminate this un- 
derbead cracking tendency. It was also noted-^^ that 
underbead cracking did not occur in the base metal 
when austenitic electrodes of either the 20% Cr, 
10% Ni, or the 25% Cr, 20% Ni type were used and 
that the Mn-Mo type of electrode coated with a 
mineral-type coating similar to that used on all 
austenitic electrodes did not produce cracking. The 
reasons for this difference in the cracking tendency 
for single or multibead deposits were not completely 
clear during the early stages of the investigation. The 


CONFIDENTIAL 


90 


WELDING 


most important reasons advanced for the noncrack- 
ing characteristics of the special Mn-Mo electrode 
were: 

1. A difference in the composition of the arc at- 
mosphere produced by the lime-type coating. It was 
felt that this difference would result in lower gas 
content, particularly hydrogen, and reduced embrit- 
tlement in the heat-affected zone. It is significant 
to note that this was the first time it was felt that the 
heat-affected zone cracking was associated with hy- 
drogen in the arc atmosphere. 

2. A smaller amount of expansion during trans- 
formation resulting in lower stresses in the weld 
region. 

As soon as the difference in the properties of the 
Mn-Mo electrode became apparent, experimental H 
plates were prepared and ballistically tested. From 
ballistic results obtained for the first plates tested, 
the following tentative conclusions were drawn: 

1. Most of the plates passed the shock test re- 
quirements established for austenitic weldments. 

2. None of the plates failed as badly as did the 
majority of H plates welded with other types of 
ferritic electrodes. 

3. A few of the H plates tested performed better 
than any H plate previously tested and closely ap- 
proximated the shock performance of unwelded 
rolled homogeneous armor. 

4. The effect on shock resistance of heat treatment 
following welding did not appear beneficial. 

As a result of these observations, the ferritic elec- 
trode development phase of the armor weldability 
problem was modified and directed towards a thor- 
ough investigation of the Mn-Mo type electrode. It 
was felt that to develop further the information al- 
ready available, pertinent studies should include the 
following: 

1. The development of an optimum composition 
of the NRC-2A electrode (Mn-Mo type) for ballis- 
tic application. 

2. The development of a modified lime-type coat- 
ing possessing better operating characteristics than 
that used on the original electrodes. 

3. A fundamental investigation of the factors in- 
volved in improving electrode coatings. This study 
also planned an investigation of the arc atmospheres 
produced by various types of electrodes. 

Accordingly, a fundamental investigation of elec- 
trode coatings was established in January 1944 at 
Battelle Memorial Institute under Project NRC-76 


(OD-36-2), Development of Improved Electrode 
Coatings. Initial work on the project was entirely 
devoted to a study of the gases present in arc at- 
mospheres and their effect on underbead cracking, 
since this subject was of particular interest in ex- 
plaining the noncracking characteristics of the Mn- 
Mo ferritic electrode. The investigation showed that 
the lime-coated ferritic and austenitic armor welding 
electrodes which do not cause underbead cracking 
produced arc atmospheres low in hydrogen with ap- 
preciable amounts of carbon dioxide. Conventional 
ferritic electrodes of the mild and alloy steel types 
with cellulosic and related coatings consistently pro- 
duced underbead cracking and are characterized by 
arc atmospheres high in hydrogen.224 a continua- 
tion of experimental work to obtain more data per- 
taining to underbead cracking in hardenable alloy 
steels led to a study of commercial and experimental 
coated electrodes. Additional tests were made using 
synthesized arc atmospheres to determine the effect 
of individual gases on underbead cracking and also 
to determine the effect of the arc upon these 
gases.225.226 These tests definitely prove that hydro- 
gen is directly responsible for underbead cracking 
in hardenable steels. Other investigations show that 
this cracking tendency is also affected by metallur- 
gical factors. 

At the request of Watertown Arsenal, later work 
on this program was devoted to determining the 
causes of weld metal porosity during metal arc weld- 
ing. Variations in porosity were found to be asso- 
ciated with the presence of hydrogen, nitrogen, and 
water vapor.226 t appears desirable to point out that 
these investigations were terminated in August 1945 
before the work had progressed to a logical conclu- 
sion. The continuation of these studies should pro- 
vide much useful information which ultimately 
should be of considerable value in minimizing arc 
welding problems. 

While the above investigations were in progress, 
work was also continuing on the armor plate weld- 
ability problem and ferritic electrode development 
program. Both investigations were closely integrated 
and were concerned with the further improvement 
and application of the NRC-2A electrode (Mn-Mo) 
to the welding of armor. A large number of H plates 
were fabricated by various procedures using com- 
mercial versions of the NRC-2A electrode, which by 
this time was being produced in appreciable quan- 
tities. The results of ballistically testing these H 


CONFIDENTIAL 


ARMOR AND ORDNANCE WELDING 


91 


plates are summarized in two reports-i^--" which 
conclude that the use of ferritic welding under con- 
trolled conditions will insure weldments possessing 
shock properties equal to or superior to correspond- 
ing austenitic weldments. Improvements were made 
in the operating characteristics of the Mn-Mo elec- 
trode and subsequent ballistic tests of weldments, 
such as an M-5 tank hull, showed that it is possible 
to fabricate successfully large armor weldments with 
this electrode.--" As a result of these observations, a 
suggested specification for the NRC-2A electrode 
was prepared-28 which was subsequently adopted as 
Ordnance Department tentative Specification AXS- 
1450. 

Attempts to improve the operating characteristics 
of the NRC-2A electrode were continued under 
Project NRC-2. The effects of changes in the con- 
stituents of the electrode coating were investigated 
to determine the effect of such changes on operating 
characteristics, porosity, and weld metal proper- 
ties.-i® This information remains incomplete be- 
cause it was considered necessary to drop this phase 
of the investigation in order to take up the more 
urgent problem of the development of electrodes for 
the repair welding of heavy cast armor. This work 
is discussed later in this chapter. 

A fundamental investigation of the isothermal 
transformation characteristics of NRC-2A weld 
metal was made under Project NRC-1, which indi- 
cated that the deposited metal from this electrode 
should consist of acicular ferrite and tempered mar- 
tensite. This structure was attributed to the rapid 
and extensive formation of acicular ferrite in the 
vicinity of 1000 F during cooling which results in 
carbon enrichment of the residual untransformed 
austenite. With the cooling rates associated with 
arc welding, no transformation occurs at inter- 
mediate temperatures and, as a consequence, mar- 
tensite rather than a ferrite-carbide aggregate is 
formed.-29'-3o 

Another study pertaining to the properties of NRC- 
2A electrode was conducted at the International 
Harvester Company, Inc., and showed that a pro- 
nounced aging effect, resulting in improved ductil- 
ity, is obtained when NRC-2A deposits are tested 
after various elapsed times at room temperature. 
Ductility is also shown to increase further as the re- 
sult of treating the weld metal for various times at low 
temperatures. This effect is believed to be associated 
with elimination of hydrogen from the deposit.^^i 


Work was also undertaken involving the post-bal- 
listic examination of ferritically welded i/^-in. H 
plates to determine the fundamental causes of poor 
shock properties. This work shows that ballistic per- 
formance is affected by several factors including weld 
metal structure and properties, armor composition, 
joint design, and welding procedure, and that failure 
usually occurs in shock-deficient metallurgical struc- 
tures adjacent to welds.^'^^ Other experiments to 
compare different types of commercial NRC-2A elec- 
trodes exhibiting good and bad shock properties also 
were carried out. 

Study of Causes and Manner of Failure 
OF Welded Joints Under Ballistic Shock 

An extensive study was made under Project NRC-1 
at the United States Steel Corporation Research 
Laboratory to determine the causes and manner of 
failure of welded armor joints subjected to ballistic 
impact. A large number of weldments primarily H 
plates but including actual components of armored 
vehicles, were examined, and the path of fracture in 
these weldments was determined and correlated 
with the zone of the joint through which the frac- 
ture traveled. In addition to establishing the mecha- 
nism for failure under ballistic shock, procedures for 
improving the shock resistance of welded joints were 
recommended.217’23.3-2.36 phe most important facts 
and conclusions revealed by these studies were: 

1. Ballistic fractures propagate through the weld, 
the bond zone, or the heat-affected zone, whichever 
has the least ability to absorb energy under shock 
loading. 

2. In weldments made with high rates of heat 
input for the cross section available, the unusually 
low rate of cooling produces a zone of weakness in 
the heat-affected portion of the parent metal next 
to the weld with the armor compositions used for 
most combat vehicles. 

3. Submerged-melt, automatic, and manual weld- 
ing of thin sections up to 1/2 in. in thickness usually 
results in cooling rates sufficiently low to permit the 
formation of a zone of weakness in the heat-affected 
zone of commercial armor compositions used for 
most combat vehicles. Ballistic failures usually occur 
in this region. 

4. Ballistic failures of weldments made with aus- 
tenitic electrodes usually occur in the weld metal 
adjacent and parallel to the interface between the 
weld metal and the heat-affected zone, provided no 


CONFIDENTIAL 


92 


WELDING 


weakness exists in the latter region. This type o£ 
fracture is believed to be caused by a linear precipi- 
tation of carbides and nonmetallics in the weld metal 
immediately adjacent to the interface. 

5. Excessive dilution of austenitic weld metal with 
parent metal (particularly in narrow joints) makes 
the weld deposit less shock resistant. Failure has 
been found to occur consistently if the iron content 
of the weld deposit is greater than 70 per cent. 

6. Weldments made using ferritic electrodes ex- 
hibit shock properties superior to corresponding aus- 
tenitic weldments and in many cases develop shock 
resistance approaching that of unwelded armor. 
These ferritic welds were made in an arc atmosphere 
low in hydrogen and the deposits are characterized 
by a microstructure consisting of acicular ferrite and 
tempered martensite which has been found to be 
associated with superior shock resistance. 

7. Conventional tensile properties, such as yield 
strength, ultimate strength, and ductility, as deter- 
mined by standard tests, do not correlate with the 
ballistic shock resistance of any part of the welded 
joint. 

Direct Explosion Test for Welded Armor 

Since it was necessary to evaluate the ballistic 
shock performance of welded armor in order to in- 
sure satisfactory service performance, it was felt that 
a simpler test for this purpose would be extremely 
valuable. As a result, an investigation involving the 
determination of shock properties by static detona- 
tion of explosive charges, either in contact with or 
closely adjacent to prime and welded armor, was 
undertaken at the Trojan Powder Company under 
Project NRC-25 (OD-76) (NS-255), Direct Explo- 
sion Test for Welded Armor and Ship Plate. Ac- 
tivity on this project resulted in the development of 
testing procedures and special explosives which, 
when detonated in direct contact with either welded 
or prime armor, enables the relative shock perform- 
ance of the steel or weldment under investigation 
to be ascertained. It is possible with this type of test 
to differentiate between the quality of different heats 
and types of armor, alloy, and mild steel, and to 
evaluate the effect of welding with different pro- 
cedures. The results obtained with the explosion 
tests closely approximate the results obtained for 
standard ballistic tests made with projectiles. How- 
ever, it should be noted that, although the explosion 
test does not exactly duplicate the ballistic test, it 


does provide a shock test of sufficient severity to ac- 
complish the same objective.^i ®^-^^ This project 
is also discussed in Section 2.2 of this report in con- 
nection with nonballistic testing methods. Although 
work has terminated in connection with the appli- 
cation of this test to armor and ordnance equipment, 
other development work in applying the explosion 
test to evaluate the performance of ship plate and 
high-tensile hull steel is being conducted for the 
Navy Department under a direct contract with the 
Bureau of Ships. 

Development of Austenitic Electrodes 

While the above investigations were being con- 
ducted, work on the development of noncracking 
austenitic armor welding electrodes was progressing 
at the Rustless Iron and Steel Corporation under 
Project NRC-2R, which was financed by the com- 
pany and conducted under the supervision of the 
War Metallurgy Committee. The objective of this 
investigation was to determine the cause of root pass 
cracking and to investigate the relative advantages 
of manganese versus molybdenum modifications of 
20% Cr, 10% Ni electrodes. Details are described in 
three reports which comprehensively cover the work 
done.238.2,39,240 xhe important conclusions drawn 
indicated that it is possible to eliminate weld metal 
cracking in austenitic deposits of the modified 20% 
Cr, 10% Ni type by properly balancing the carbon, 
nickel, chromium, manganese, and molybdenum 
contents. Modifying the composition of the weld 
deposit so that a small amount of delta ferrite is 
developed minimizes the tendency for cracking. 
There appears to be an optimum amount of this 
phase which will give best results. Satisfactory elec- 
trodes can be made using either manganese, molyb- 
denum, or combinations of these metals, provided 
proper alloy balance is maintained. A composition 
balancing factor was developed which relates the 
carbon and alloy content of the weld to its structure. 

Significantly, it was disclosed that although both 
the mechanical properties and the cracking tendency 
of austenitic electrodes are affected by changes in 
composition, no relation exists between the ballistic 
properties of austenitic weldments and the compo- 
sition of the deposited electrode. The ballistic per- 
formance of several types of rolled homogeneous 
armor welded with austenitic electrodes, as evalu- 
ated by a direct explosion test, revealed variations 
which were ascribed to the armor used in the tests. 


CONFIDEN UAL 


ARMOR AND ORDNANCE WELDING 


93 


Application of Large Diameter Electrodes 

A survey was made by the War Metallurgy Com- 
mittee on the application o£ large diameter austen- 
itic electrodes to the welding o£ armor. It was con- 
cluded that, while the use o£ large-size electrodes 
in. and 1/2 in.) would materially increase rates o£ 
production, in armor applications their use should 
be limited to sections not less than I 1/2 in. thick, 
since ballistic tests indicated that the high heat input 
associated with large diameter electrodes produced 
shock-deficient metallurgical structures in plates up 
to 1 in. thick. 

Low-Temperature Ballistic Performance of 
Welded Armor Plate 

As a result of the poor ballistic shock performance 
exhibited by prime and welded armor at subnormal 
temperatures, the Army Ordnance Department’s 
Tank Automotive Center in Detroit requested an 
investigation of the causes for failure of welded 
plates tested during the Canadian Cold Test Pro- 
gram of 1942-1943. This study was conducted also 
by the United States Steel Corporation Research 
Laboratories under Project NRC-1 and included H 
plates welded by the automatic Unionmelt process, 
H plates manually welded using 20% Cr, 10% Ni, 
4% Mn electrodes, and H plates manually welded 
with 20% Cr, 10% Ni, 2% Mo electrodes. Because of 
the urgency of the work, these problems were as- 
signed to research laboratories of the United States 
Steel Corporation, the International Nickel Com- 
pany, and the Climax Molybdenum Company, re- 
spectively, with overall coordination provided by 
the United States Steel Corporation investigators. 

The investigation of the automatic process dis- 
closed that the path of fracture in the ballistically 
tested H plates was predominantly in the heat- 
affected zone of the armor adjacent to the weld. The 
primary cause of failure in this region is believed to 
be due to the combined effect of unfavorable armor 
composition and to the high rate of heat input char- 
acteristic of the submerged-melt process, both of 
which result in the formation of free ferrite and 
other high-temperature shock-deficient transforma- 
tion products. Other contributing factors, which ap- 
pear to be magnified at subnormal temperatures, are 
the presence of local stress concentrations resulting 
from excessive weld reinforcement and defective 
welding. Recommendations for improving both aus- 


tenitic and ferritic Unionmelt welded armor are also 
presented in the report of this work.233 

The investigation of H plates manually welded 
with Cr-Ni-Mn austenitic electrodes attributed fail- 
ure at low temperatures to excessive weld metal 
hardness in the root passes resulting from a low 
austenitic margin.^^^ Studies of H plate failures 
manually welded using Cr-Ni-Mo austenitic elec- 
trodes showed that the fracture path obtained in the 
low-temperature tests occurs at the interface be- 
tween the weld and base metals and appears to al- 
ternate between these regions.-^^ This type of failure 
was attributed to shearing stresses developed at the 
weld interface as a result of cooling the armor and 
the austenitic weld metal which possesses greatly dif- 
ferent coefficients of expansion at low temperatures. 
Other investigations have shown a linear precipita- 
tion of carbides and nonmetallics in the weld metal 
very close to the base metal interface, a factor which 
undoubtedly plays an important part in failure at 
this location. 

Development of Welded Backup Strips 

Research involving the development of backup 
materials for welded armor joints was established in 
May 1943 at Battelle Memorial Institute under Proj- 
ect NRC-59 (OD-82), Non-Metallic Welding Back- 
Up Strips for Armor Plate Joints. This program was 
particularly concerned with nonmetallic materials 
because of difficulties attendant to removing steel 
bars and because of the fact that copper tends to 
melt, diffuse, and thereby alter the composition of 
the first weld pass. This sometimes causes porosity 
and cracking in certain weld metal compositions. 
Mineral-coated metallic strips and tamped granular 
ceramic materials were developed and applied with 
considerable success to austenitic and ferritic weld- 
ments in armor, alloy, and mild steels.2^2,243,244 

Effect of Oxygen Cutting on Weldability 

Another project, directly related to the armor 
weldability investigation, was initiated as the result 
of a request made by the Army Ordnance Depart- 
ment’s Tank Automotive Center in Detroit. This 
project. Project NRC-71 (OD-136), Effect of Oxygen 
Cutting on Weldability of Armor Plate, was estab- 
lished in October 1943 at the Air Reduction Com- 
pany, Inc., to study cracking associated with oxygen 
cutting, grooving, and gouging operations on rolled 
and cast homogeneous armor. Originally it had been 


CONFIDENTIAL 


94 


WELDING 


contended that cracks resulting from flame cutting 
operations made preparatory to welding were par- 
tially responsible for poor ballistic properties. 
Therefore, one of the primary purposes of this proj- 
ect was to investigate conditions leading to the crack- 
ing in the oxygen cutting of rolled homogeneous 
armor. It was demonstrated that with appropriate 
cutting procedures rolled homogeneous armor in 
plate thicknesses up to 3 in. could be oxygen cut 
without cracking. Large inclusions, shrinkage stresses 
in internal corners of small radii cuts, and residual 
stresses resulting from straightening operations were 
found to be responsible for cracking in oxygen-cut 

plate.245 

Later work on this project was primarily devoted 
to a study of cutting, grooving, and gouging opera- 
tions on heavy sections of cast armor. Again it was 
found that with appropriate procedures cast armor 
of 4 in. thicknesses could be cut, grooved, and gouged 
without cracking. Shrinkage stresses in internal cor- 
ner cuts with radii less than 1 in., low ductility, and 
especially inclusions are the primary reasons for 
cracking in cutting or scarfing operations on cast 
armor. Recommendations for the cutting of rolled 
and cast armor were also prepared.-^® 

Welding of Face-Hardened Armor and 
Boron-Treated Homogeneous Armor 

Although the problems attendant to the welding 
of face-hardened armor were considered urgent dur- 
ing the early part of World War II, greater empha- 
sis on shock properties with the resulting increase in 
the use of homogeneous armor somewhat reduced 
the importance of this subject. Three projects were 
initiated, however: a correlation project, NRC-16R 
(OD-74), Welding of Face-Hardened Armor, at 
Rock Island Arsenal; Project NRC-24 (OD-74), The 
Development of a Process for Manufacturing and 
Welding of Face-Hardened Armor, at the Buick 
Motors Division of General Motors Corporation; 
and Project NRC-30 (OD-74), Development of Proc- 
esses for the Manufacturing and Welding of Case- 
Carburized Armor Plate from Non-Alloy Steels, also 
at the Buick Motors Division of GMC. 

The work on Project NRC-16R showed that it was 
impossible to weld face-hardened armor of the high 
nickel-molybdenum type with complete freedom 
from cracking by any procedure in which weld metal 
comes in direct contact with the carburized surface. 
No difficulty was experienced in welding the uncar- 


burized surface of this type of armor. Special pro- 
cedures involving precladding were developed which 
resulted in satisfactory welds in this material.^^^ 

Work on Project NRC-24 was primarily concerned 
with the development of a machinable type of face- 
hardened plate by additions of boron in the form 
of special addition agents, such as Grainal, to a con- 
trolled hardenability carbon-manganese steel. Tests 
showed this material to be readily weldable, but 
difficulties were encountered in duplicating plate ma- 
terial which made the results rather inconclusive.®"^ 

In Project NRC-30, Manufacture and Welding of 
Case Carburized Armor Plate from Non- Alloy Steels, 
special attention was paid to the effects of boron and 
other alloying additions on ballistic properties and 
weldability of armor steel. It was apparent from this 
work, as well as that on Project NRC-29, Manufac- 
turing and Welding of Homogeneous Armor Plate 
from Non-Alloy Steels, that boron does not materially 
affect the weldability of armor. It is to be noted that 
some of the reported developments seem unsuited 
for welded applications.®^ ®®'^^®-^*^^ 

The above-mentioned projects dealing with boron- 
treated steels are also discussed in Sections 2.3.1 and 
2.3.2, because they were concerned principally with 
the development of armor plate rather than with 
the welding of such plate, although the latter is an 
important consideration in its fabrication. 

Stress Relief of Weldments 

Shortly after the start of the armor welding pro- 
gram, research was initiated to determine the stress 
relieving characteristics of steels used in the fabri- 
cation of ordnance equipment, such as gun mounts. 
Investigations in this field were established at Ohio 
State University under Project NRC-3 (OD-34-2), 
Stress Relief of Weldments for Machining Stability, 
and at Rock Island Arsenal under Correlation Proj- 
ect NRC-17R (OD-34-2), Stress Relief of Welded 
Joints. In both these projects the variables present 
in stress relieving low-alloy steels and methods of 
measuring residual stresses were investigated. In ad- 
dition, the problem of dimensional stability after 
machining was given special attention in Project 
NRC-3. These investigations indicate that (1) a 
temperature of at least 1100 F is necessary to elim- 
inate effectively residual stresses in alloy steels, (2) 
temperature is more effective than time in reduc- 
ing residual stresses, (3) thermal stress relief just 
below the critical temperature greatly improves 


L 


ARMOR AND ORDNANCE WELDING 


95 


the stability of weldments after machining, and 
(4) both the magnitude of residual stress and the 
distortion which occurs on machining weldments 
in the as-welded condition are proportional to the 
yield strength of the steel at stress relieving tem- 
per a ture.-^^-^”’^ 

Repair of Cast Armor by Welding 

During 1944 the problem of repairing heavy cast 
armor became of extreme importance because of 
the need for heavy tanks. As a result of a request 
of NDRC initiated by the Office of the Chief of 
Ordnance-Detroit for the extension of Army Ord- 
nance problem OD-36-2 to include the development 
of suitable electrodes for repair purposes, the pro- 
grams of both Project NRC-1 and Project NRC-2 
were modified to carry on this additional work. The 
basic problem was to develop a weld metal which 
when heat treated in accordance with the pro- 
cedures used for heavy armor castings, would pro- 
vide shock and penetration-resisting properties 
equivalent to heat-treated cast armor. Under Proj- 
ect NRC-1 at the United States Steel Corporation 
Research Laboratories, the objective was to recom- 
mend electrode compositions which, when deposited 
and heat treated, would develop fully martensitic 
structures at the center of 6-in. sections and to eval- 
uate the suitability of these electrodes for the in- 
tended purpose. It is believed that the presence of 
tempered martensite or certain low-temperature 
bainites is essential to the development of good 
shock-resisting properties, and it was desired that 
these properties be realized at the highest practical 
hardness level in order to obtain adequate resistance 
to penetration by armor-piercing projectiles. 

The work under Project NRC-2 at the Combustion 
Engineering Company was designed to produce and 
investigate the welding characteristics of electrodes 
recommended for the above purposes. It was neces- 
sary to terminate work on both phases of this investi- 
gation before it had been carried to a logical con- 
clusion and as a result only preliminary work is 
reported. Several electrodes were developed, how- 
ever, which appeared promising for the intended 
purpose. 

During the production of combat vehicles with 
heavy cast armor, considerable aid was furnished pro- 
duction foundries by members of the welding super- 
visory staff of the War Metallurgy Committee in the 


form of field service and consultation on repair weld- 
ing problems. It is noteworthy that it was necessary 
to use the NRC-2A electrode, developed in the 
NDRC welding program, for the production repair 
of armor castings pending the development of better 
electrodes. All other commercial ferritic and austen- 
itic electrodes were found to be unsuited for this ap- 
plication in Army Ordnance Department tests. The 
availability of this electrode undoubtedly speeded 
heavy tank production at a critical period. It is felt 
that this field service was one of the more important 
contributions of the War Metallurgy Committee and 
NDRC during the later stages of World War II.^^s 

Development of an Electrode for Welding 
High-Strength Structural Steels 

Another problem of considerable importance dur- 
ing the late stages of World War II arose because of 
the necessity for weight reduction in ordnance equip- 
ment. Experimental designs for gun mounts, 
tank transporters, etc., have been proposed using 
quenched and drawn steels of 90,000 psi minimum 
yield strength. The use of heat-treated steels in the 

120.000 psi yield strength range has also been contem- 
plated. As a result, there was an urgent need for the 
development of usable lime-coated alternating-cur- 
rent ferritic electrodes possessing equivalent yield 
strengths for fabricating these materials. However, 
these steels are essentially the same as those used for 
light homogeneous armor and, therefore, weldability 
problems are similar. 

At the request of the Ordnance Design Sub-Office, 
Franklin Institute, the Office of the Chief of Ord- 
nance requested NDRC for an extension of the scope 
of problem OD-36-2 and for this purpose a develop- 
ment program was added to Project NRC-76, Devel- 
opment of Improved Electrode Coatings, already 
being conducted at Battelle Memorial Institute. Al- 
though work on this project was terminated before 
the completion of the proposed program, two very 
promising electrodes were developed possessing 

90.000 and 120,000 psi yield strengths with good duc- 
tility.^^^ Additional work to determine the suita- 
bility of these electrodes for use under severe loading 
conditions is essential before definite recommenda- 
tions can be made for their use in high-strength, 
lightweight structural applications. Important field 
service and consultation in connection with this 
general problem was also furnished the fabricators 


96 


WELDING 


of experimental equipment by members of the 
welding supervisory staff of the War Metallurgy 

Committee.253 

613 Weldability 

Although a fundamental study of the weldability 
of steels was not considered as important early in 
World War II as a more direct approach to special 
subjects, such as the armor problem discussed in the 
previous section, it was felt that information which 
would enable the selection of optimum arc welding 
conditions for steels used in the fabrication of tanks, 
gun mounts, and other ordnance equipment would 
be extremely useful. Because of the breadth of the 
general weldability problem, however, it was deemed 
desirable to limit initial studies to a particular phase 
of the subject in order to reduce the number of vari- 
ables under simultaneous consideration. Since it was 
the considered opinion of many in the welding in- 
dustry that the production of a ductile metallurgical 
structure in the heat-affected zone of the base metal 
was of paramount importance in avoiding welding 
and service difficulties, early work was restricted to 
a study of the effect of welding conditions on the 
heated base metal adjacent to welds and the utiliza- 
tion of this information to select welding conditions 
for different steels. In recognizing the significance of 
this aspect of weldability, it was not intended to 
minimize the importance of the electrode deposit, 
since it is apparent that the interrelation of both 
base metal and weld metal properties determine the 
subsequent behavior of the weld in service. 

It is of particular interest to note the belief in 
1942 that high ductility in the heat-affected base 
metal was essential to avoid such welding and serv- 
ice difficulties as cracking and poor ballistic proper- 
ties. This conception undoubtedly was prompted to 
a great extent by the cracking observed in the 
heated region adjacent to welds made in harden- 
able steels which were made by using ferritic elec- 
trodes without preheat. Since that time, the under- 
bead cracking phenomenon has been explained.^^s 
The relatively poor shock properties of the highly 
ductile elevated temperature transformation prod- 
ucts has been demonstrated, as well as the fact that 
ductility measurements do not provide a valid 
method for predicting service performance particu- 
larly under severe loading conditions.^"^"^ The re- 


sults of the initial weldability investigations, which 
are briefly summarized below, should therefore be 
reviewed in the light of more recent findings. 

Both the properties and structures of the base 
metal adjacent to the weld are necessarily influ- 
enced by a number of factors. It was believed that 
the most important of these were the rate of cooling 
of the heated base plate material and the hardening 
characteristics of the steel under consideration. 
Therefore, the first phase in the investigation of 
the effect of welding conditions on the heat-affected 
base metal involved the determination of the rate 
of cooling in this region. This was approached by 
making direct measurements and hardness meas- 
urements. Both lines of attack were resorted to, since 
it was realized that great difficulty was associated 
with the direct measurement of welding cooling 
rates and the subsequent extension of this data by 
mathematics to include a wide variety of conditions. 

The method of attack utilizing hardness measure- 
ments was followed in Project NRC-9 (OD-37-1), 
Evaluation of Weldability by Direct Welding Tests, 
established at Lehigh University in April 1942. The 
procedure used involved the determination of the 
maximum hardness in the heat-affected base plate 
for given energy inputs, plate thicknesses, and joint 
designs, and the further relation of this hardness to 
the hardness of a standard end quenched Jominy 
hardenability bar of the same steel treated to re- 
produce the austenitic grain size found adjacent to 
the weld. It was assumed that corresponding hard- 
nesses in the heat-affected zone and in the Jominy 
bar would represent equivalent cooling conditions, 
and in this manner welding conditions could be 
expressed in terms of Jominy positions. By heat 
treating to various hardness levels notched bend 
specimens from the material to be welded, the rela- 
tive ductility corresponding to these hardness levels 
can be obtained from measurements of the angle 
at maximum load during slow bend tests of these 
specimens at room temperature. Thus, cooling rates 
could be correlated with ductility by relating both 
of these factors to hardness, and the selection of 
welding conditions to be used under given circum- 
stances then resolves itself into a specification of 
the required ductility, which is a matter of expe- 
rience and judgment. 

To reduce the amount of experimental work nec- 
essary to provide working charts from which in- 
formation applicable to a wide range of welding 


CONFIDENTIAL 


ARMOR AND ORDNANCE WELDING 


97 


conditions (cunent, arc voltage, and travel speed), 
plate thicknesses, and joint designs can be obtained, 
the assumption was made and verified that the cool- 
ing effect of various weld geometries can be related 
to the cooling effect exerted by metal within a cer- 
tain distance of the weld. With the charts prepared 
in this manner, a quantitative prediction of the 
cooling rate for any combination of welding condi- 
tions, plate thicknesses, and joint design may be 
made without experiment. Then with hardness- 
ductility relationships established for the steel 
under consideration, welding conditions may be 
selected to obtain the desired ductility in the heat- 
affected zone adjacent to the weld. 256 . 257,258 

A program to undertake actual measurement of 
cooling rates in the heat-affected zone immediately 
adjacent to welds was established in March 1942 at 
Rensselaer Polytechnic fnstitute under Project 
NRC-10 (OD-37-1), Evaluation of Weldability by 
Direct Measurement of Cooling Rates, fn this in- 
vestigation, experimental techniques were devel- 
oped to measure cooling rates associated with dif- 
ferent welding conditions. The experimental data 
obtained were extended by means of mathematics 
to include a wide variation in welding conditions 
through modifications of the transient heat flow 
equations. The cooling rate data so obtained may 
be applied to particular steels for the purpose of 
securing any desired metallurgical structure ad- 
jacent to a weld through the use of the end-quenched 
Jominy hardenability test and isothermal trans- 
formation data. Procedures for applying this infor- 
mation to the solution of welding problems were 
developed.259 

Another investigation, closely related to the 
above studies, was initiated for the purpose of 
studying the mechanism of heat flow during arc 
welding. This investigation, which did not involve 
any consideration of the metallurgical aspects of the 
problem, became Project NRC-11 (OD-37-1), Evalu- 
ation of Weldability by Correlation of Electrical and 
Heat Constants, established at Columbia University 
in April 1942. The investigations were conducted 
using the method of electrical analogy in which elec- 
trical networks are used which follow the same 
mathematical laws that apply to transient heat flow. 
General cooling curves were established for a variety 
of welding conditions and were found to be in close 
agreement with cooling curves determined by direct 
thermal measurements. An interesting and impor- 


tant feature of the electrical analogy method is that 
experiments need not be carried out in the same 
time in which the heat transfer phenomenon oc- 
curs. The time for the electric experiment may be 
made shorter or longer than the actual interval of 
heat flow on a scaled basis, which simplifies the pro- 
cedure used for making measurements. Although 
the data accumulated in this investigation are in- 
complete, the validity of the method is evident and 
in all probability it may be applied to other weld- 
ing problems involving transient heat flow.^^o 

Under Project NRC-65 (OD-123), Evaluation of 
Factors Affecting Crack Sensitivity of Welded 
Joints, a research program was conducted at 
Rensselaer Polytechnic Institute. The principal 
emphasis of this investigation was placed on a study 
of the effects of the length of weld, plate thickness, 
plate composition, electrode, and welding variables 
upon the stresses produced. Welds were made using 
both transverse and longitudinal restraint, and 
considerable information was obtained for each 
case.261 Another phase of this project was concerned 
with the magnitude of the stress at which cracking 
occurs in welds made under conditions of restraint. 
This condition is referred to as the cracking limit 
and comparisons were made to determine the sig- 
nificance of plate thickness, joint geometry, and type 
of electrode. The results of a limited number of 
comparisons made using comparatively thin plates 
indicate that the cracking limit is obtained at a 
stress value in the weld surface of approximately 80 
per cent of the ultimate strength of the deposited 
metal, and that the shape of the cross section in the 
weld deposit significantly affects the cracking ten- 
dency in first pass deposits. These data were obtained 
using E-6020 and E-6010 electrodes in welds made 
in 1 / 2 -in. plate without backing strips. Different 
results were obtained for welds made with backup 

bars.262 

Another investigation conducted at Lehigh Uni- 
versity, Project NRC-66, Methods of Testing WelT 
ability of Steel Plates and Shapes, developed a 
method for quantitatively comparing the degree 
of restraint at which a weld cracks during cooling in 
steel plates of various compositions when all other 
conditions are maintained constant. A special fin- 
type specimen in which the restraint can be varied 
was designed for this purpose. Variations were noted 
in the cracking tendency of several plain carbon and 
low-alloy steels, and it was found that the test 


CONFlDENTfAL 


98 


WELDING 


method could be used to compare electrodes, in 
terms of the restraint at which cracks occur, with 
any chosen plate composition. 

An investigation of the cracking tendency of 
several grades of commercial electrodes using the 
fin-type weldability specimen revealed differences 
in the quality of these electrodes. A study of the ef- 
fect of preheat indicated that crack sensitivity is 
reduced proportionately as the plate temperature 
is raised.263 


Resistance Welding 

Several nonrelated resistance welding research 
programs were undertaken as needed to provide in- 
formation considered necessary for the successful 
fabrication of war material, particularly aircraft. 
This work included investigations of the spot weld- 
ing of light armor and alloy steels, the flash welding 
of aircraft steels, the spot welding of magnesium 
alloy sheet, and nondestructive test methods for spot 
and flash welds. Although fundamental data of 
major importance resulted from this work, it ap- 
pears desirable to point out that these studies are 
representative of only a small portion of wartime 
resistance welding research. 

Spot Welding 

Investigations conducted prior to World War II 
indicated that spot welding offered a promising 
method for joining steels up to 1/2 in. in thickness. 
The possibility of fabricating light armor and alloy 
steels in this thickness range offered interesting pos- 
sibilities and was made the subject of an investiga- 
tion at Rensselaer Polytechnic Institute under Proj- 
ect NRC-12 (OD-85), Spot Welding of Armor Plate 
and Low-Alloy Steels. Attempts to utilize early in- 
formation led to a complete investigation of the 
fundamentals of spot welding heavy plate, together 
with an investigation of the feasibility of heat treat- 
ing spot welds in the welding machine. As a result 
of this work, which included the development of 
control equipment, measurement techniques, and 
a test for weld properties, a general procedure was 
formulated which permits the selection of optimum 
welding and heat-treating conditions to be used for 
any given thickness combination of hardenable 
steels. Procedures were also developed for spot weld- 
ing alloy steel clip attachments to both homoge- 


neous and face-hardened armor. In ballistic tests 
these weldments demonstrated shock resistance 
properties equivalent to the armor itself. An in- 
teresting comparison of the merits of continuous and 
pulsation welding for this application showed that 
the continuous process is to be preferred.‘-®^*265 

To ascertain the feasibility of predicting weld 
strengths from radiographic or fluoroscopic images. 
Project NRC-56, Radiographic and Fluoroscopic 
Methods of Inspection of Spot Welds in Aluminum 
Alloys, was established at California Institute of 
Technology in March 1943. In this investigation, a 
new short source-film-distance technique was devel- 
oped for spot-weld radiography which enables de- 
terminations of weld structure and quality to be 
made and also provides a consistent and positive 
method for determining the strength of spot welds 
made in Alclad 24S-T and XB75S-T sheet in equal 
or unequal thickness combinations up to a ratio of 
3:1 266 As this technique involves the unorthodox 
procedure of placing the X-ray tube very close to the 
film, it is applicable only to the radiography of thin 
specimens. The interpretation of spot-weld radio- 
graphs given in the final report on this project was 
adopted and included in the Navy Bureau of Aero- 
nautics Specification PW-6A, Amended, covering 
spot welding process control and inspection for naval 
aircraft. 

A study of the fluoroscopic method of spot-weld 
inspection showed that further development, in- 
cluding a major improvement in screen contrast 
and definition, was necessary in order to attain the 
reliability and accuracy exhibited by the radio- 
graphic method. In general, those aluminum alloys 
with high percentages of radiographically dense 
alloying constituents, such as zinc and copper, will 
produce spot-weld images which may be used for 
process control, whereas alloys without dense con- 
stituents cannot be handled in this fashion.^^^^ 

The feasibility of spot welding magnesium alloy 
sheet material was investigated at Rensselaer Poly- 
technic Institute under Project NRC-68, Spot 
Welding of Magnesium Alloys. It had been demon- 
strated in early studies that for the production of 
sound and consistent spot welds the surface of the 
sheets to be welded must be carefully prepared 
either chemically or mechanically. Therefore, a 
major objective of this investigation was to develop 
a single chemical solution which would clean all 
varieties of magnesium sheet at room temperature. 


ARMOR AND ORDNANCE WELDING 


99 


As a result of extensive work on this aspect of the 
problem, a chemical method for preparing mag- 
nesium sheet for spot welding was developed. The 
solution used contained 10 per cent chromic acid 
with an addition of 0.05 per cent anhydrous sodium 
sulphate.-^® 

Since magnesium alloys are similar to aluminum 
alloys in that they have relatively high electrical and 
thermal conductivity and low melting points, the 
essential requirements in equipment and technique 
for spot welding magnesium alloys are similar to 
those required for aluminum alloys. Optimum 
conditions for spot welding equal thicknesses of 
three commercial compositions of magnesium alloy 
sheet in several tempers and thicknesses were deter- 
mined and are presented in the final report on the 
project together with a description of methods used 
for testing and examining spot welds in these 
alloys.-®® 

Flash Welding 

Project NRG- 13 (OD-86), Flash Welding of Alloy 
Steels for Ordnance, was established at Battelle 
Memorial Institute in April 1942. 

In order to investigate the effect of process vari- 
ables on the production of high-quality welds, dif- 
ferences resulting from varying the electrical and 
mechanical factors associated with the process were 
appraised by metallurgical examination and me- 
chanical tests. It was demonstrated in the investiga- 
tions that high-quality flash welds made in SAE-4130 
steel heat treated to 160,000 psi are as strong as the 
parent material. Defective welds resulted from de- 
carburization at the weld interface and the presence 
of oxide films at this location.-^® -'^ 

Attempts were made to eliminate these defects by 
surrounding the flashing surfaces with nonoxidiz- 
ing atmospheres during welding. Dry hydrogen, dry 
carbon monoxide, and natural gas were shown to 
have possibilities as protective atmospheres. The re- 
sults of these tests show that defects are obtained 
even with these atmospheres, if the electrical or me- 
chanical conditions are not properly established. It 
was noted, however, that the variation in welding 
conditions which can be tolerated without affecting 
the production of high-quality welds is greater when 
the protective atmospheres are used.^^s 

Part of the activity of this project included the 
translation of the German book by Hans Kilger, 


published in 1936, which discusses the fundamentals 
of the flash welding process.-"® 

The difficulty of determining the quality of flash 
welds in production without resorting to destruc- 
tive tests led to the establishment at California In- 
stitute of Technology of Project NRC-57 (OD-86), 
Non-Destructive Testing of Flash Welds. Among 
the many methods investigated, four were found 
which may be used with limitations for the detection 
of flash-weld flaws. These methods include the 
standard magnetic powder test and several special 
tests.-^’^ -’’’® Of these tests, one in which the devia- 
tions from a normal eddy-current flow pattern in 
the region of the weld are measured is considered to 
offer the greatest possibility for production testing. 
In this test, deviations in the eddy-current pattern 
are produced by flaws in the weld. It is of particular 
interest to note that the eddy-current test may be 
successfully applied to the testing of nonferrous 
metals.-®® 

To determine the research needs in the field of 
aluminum alloy flash welding, Survey Project SP-23, 
Flash Welding of Aluminum, was carried out by the 
War Metallurgy Committee in mid 1944. This sur- 
vey showed that the application of this process to 
aluminum alloys was in its infancy. No standardized 
welding techniques existed, and there were consid- 
erable differences of opinion regarding proper 
methods for welding and the design of machines. 
On the basis of rather inconclusive evidence, it ap- 
pears that it may be possible to produce flash-welded 
joints possessing 90 per cent of the tensile strength 
of the parent alloys. From expressed opinions, it is 
believed that most aluminum alloys can be suc- 
cessfully flash welded and that heat treatment after 
welding will probably improve the joint properties 
in certain compositions.-®^ No NDRC research 
projects were established on this subject. 

6.1.5 Indexing of Division 18 Reports on 
Welding of Armor and Ordnance 

An index of the Division 18 reports on the weld- 
ing of armor, ordnance steels, and structural steels 
issued during the period 1942 to 1944 was prepared 
by the Research Information Division of the War 
Metallurgy Committee. This index^ss gives a sub- 
ject list of the various projects with the reports issued 
on each, a brief abstract of the contents of each 


100 


WELDING 


report, and a subject index of the reports. It lists also 
the steels and electrodes used in the investigations. 

6 2 SHIP WELDING AND WELDED 

STEEL SHIPS 

Introduction 

Several welded tankers and dry-cargo ships suf- 
fered severe structural failures during the winter 
of 1942-43. Failures occurred both at sea and when 
ships were moored in quiet harbors. These failures 
were of the brittle cleavage type and often propa- 
gated with explosive rapidity, in some cases the 
reports having been heard as far as a mile away. 
The fractures which started at discontinuities in 
the hull structure occasioned by fabrication and 
design traveled transversely across the hull struc- 
ture, in several instances splitting the vessel in two. 

At the outset of the extensive war shipbuilding 
program of the Merchant Marine, it was decided 
that the ships were to be fabricated by welding. 
Although the experience available at that time bear- 
ing on the operation and fabrication of welded ships 
was limited, it was decided to adopt this method of 
construction rather than riveting because welding 
reduced greatly the construction time and saved 
materials. Both of these factors were, of course, of 
paramount importance. 

Investigations following these hull failures re- 
vealed the fact that, although in many instances the 
workmanship was not satisfactory, the shipbuilding 
materials complied with the existing specifications. 
Recognition of the seriousness of faulty workman- 
ship led to immediate improvements through edu- 
cation and extended supervision and inspection. 

At that time it was the considered opinion of the 
majority of technical shipbuilding personnel that 
a prime factor in the cause of these failures was the 
existence of residual stresses locked in the hull struc- 
ture generally, but particularly in the welds and 
adjacent material. This opinion was based on the 
appearance of cracks parallel to the weld which oc- 
curred when a weld was made under high restraint 
and the proper welding sequence had not been fol- 
lowed. These cracks were believed to be caused by 
high transverse stresses resulting from the welding 
operation. It was also believed that such high trans- 
verse residual stresses were present to a degree in all 
welds and when they were combined with the work- 


ing stresses of the hull, particularly at welded butts, 
hull fractures resulted. For this reason great empha- 
sis was placed on following a prescribed welding 
sequence in order to avoid or at least minimize resid- 
ual stresses. In consequence, when the research 
program for investigating the structural failure of 
welded ships was started, prime emphasis was placed 
on a study of welding stresses. 

Through the recommendations of the War Metal- 
lurgy Committee and with the cognizance of the 
U. S. Maritime Commission, the U. S. Coast Guard, 
and the American Bureau of Shipping, NDRC had 
established the first research project in this general 
field by June 1943. As time went on, the need for 
investigating the ship failure problem from other 
viewpoints became apparent. This resulted in the 
establishment of additional research projects so that 
by August 1945, fifteen investigations in this field 
were in progress, or had been completed. 

6.2.2 Welding Stresses in Ship Construction 

Two research investigations were established at 
the University of California to investigate welding 
stresses. Project NRC-64 (NS-304), Residual Stresses 
in Ship Welding, was concerned with studies of 
residual stresses in typical ship weldments as well 
as those in actual ship subassemblies, while Project 
NRC-74 (NS-305), History of Residual Stresses in 
Welded Ships, dealt with investigations of both 
residual stresses in actual ship subassemblies and the 
locked-in stresses in the hull structure of completed 
ships. Residual stresses are defined as the weld- 
ing stresses produced in free subassemblies, while 
locked-in stresses include also the stresses result- 
ing from other fabrication and assembly processes. 

The research projects to study residual stresses 
were organized to determine the magnitude and dis- 
tribution of stresses in typical ship weldments, etc. 
To determine these stresses, a method of relaxing 
plugs containing resistance strain gages was per- 
fected. Weldments consisting of 1 -in. -thick ship 
plates and ranging in size from 4-ft by 6-ft to 27-ft 
by 57-ft ship subassemblies were investigated2®^'284 
The effect on the magnitude and distribution of 
residual stresses was determined as a function of such 
variables as manual and Unionmelt welding,^®^ 
welding sequences,283-286 e]ectrodes,22i-223,284 

straint, 285.286 preheating,285,286 peening, 288.286 


CONFIDENTIAL 


SHIP WELDING AND WELDED STEEL SHIPS 


101 


chanical loading along a butt weld,-®^ and the 
effect of controlled low-temperature stress relief.-*® 

The investigation of the locked-in stresses in com- 
pleted ships, Project NRC-74, was organized to de- 
termine: (1) stresses in the decks of six recently 
completed vessels and eight ships that had been in 
service, 2*7 the history of the changes of the locked-in 
stresses starting from completed deck subassemblies 
and tracing these stresses through construction, 
launching, outfitting, and loading, as well as during 
the first voyage of two Liberty ships; 2 ** (2) the effect 
on the locked-in stresses of the hogging and sagging 
test of three type T-2 tankers ;2*9-29o (3) the stress 
effects owing to temperature gradients through the 
hull structure;2®i (4) the magnitude and distribu- 
tion of locked-in stresses in the decks of 21 Victory 
ships constructed in three Pacific Coast yards;292 the 
stress effects of welding a large hot deck subassembly 
into a cooler hull structure; 2 ®* and the use of X-ray 
diffraction measurements for determining stresses 
in hot-rolled plate.2®^'295 

Some significant conclusions from these investiga- 
tions are as follows: 

1. The magnitude and general pattern of the resid- 
ual welded stresses existing in very large weldments 
up to 27 ft by 57 ft can be obtained in panels as small 
as 6 ft by 4 ft. These stresses are sufficiently repro- 
ducible either by Unionmelt or manual welding to 
enable significant effects of different controlled vari- 
ables to be determined. 2 **> 28^-86 

2. In butt welds of free subassemblies made from 
1-in. plate, the longitudinal residual stresses along 
the center line of the weld reach a magnitude of ap- 
proximately 47,000 psi in tension throughout the 
length, except in the 9 inches adjacent to each end 
where they decrease to zero at the ends. The trans- 
verse residual stresses are low tension usually less 
than 10,000 psi, except near the ends of the weld 
where they change to compression, reaching values 
of from 20,000 to 30,000 psi at the ends.27®.283,285,28c* 

3. Welding sequence in general does not affect the 
magnitude of residual stresses in free subassem- 
blies.2*® 

4. Longitudinally along the deck welds of com- 
pleted Liberty ships'^ stresses were tensile and ranged 
from 20,000 to 50,000 psi with an average value of 
36,000 psi. Stresses transverse to the welds reach a 

aThe computed tensile deck stresses resulting from the bend- 
ing moments were essentially the same in all ships ranging 
from 2,200 psi to 4,700 psi with an average value of 3,400 psi. 


maximum value of 11,000 psi in tension with an 
average value very close to zero. It was determined 
also that these stresses are not reduced appreciably 
by normal service287 since only a very small fraction 
of the welded ships have failed. Therefore, it was 
concluded that the locked-in stresses do not con- 
tribute materially to such failures. Similar investiga- 
tions on board C-4 troopships29® and T-2 tank- 
ers2*8.29o also were completed. 

5. The locked-in stresses at selected points away 
from welds in the general deck area abreast of a No. 
3 hatch of completed Liberty and Victory ships are 

generally compressive. 2*7.202 Liberty ships, 

the locked-in stresses ranged from 1,500 psi in ten- 
sion to 9,800 psi in compression with an average value 
of 5,200 psi in compression.287 in the Victory ships 
these locked-in stresses range from 8,800 psi in ten- 
sion to 16,600 psi in compression with an average 
value of approximately 7,600 psi in compression. 
Those near the gunwales of completed Victory ships 
are generally tensile and reached a maximum value 
of 5,900 psi. Higher values of locked-in tensile stresses 
were observed at other locations in the deck .292 


6.2.3 Effect of Multiaxial Loads on the 
Behavior of Ship Steel 

As the investigations dealing with welding stresses 
progressed, it became apparent that these stresses 
were not important factors contributing to the struc- 
tural failure of welded ships and that other phases 
of the problem should be investigated. 

Upon review of the brittle characteristics of frac- 
tured material removed from ships that had failed, 
questions were raised regarding the state of stress to 
which this material had been subjected. It was felt 
that the hull steel must have been subjected to a 
complex state of stress since, as manifested by the 
low degree of ductility exhibited by the fracture, 
shear flow had been inhibited. When samples of steel 
taken close to the fracture were subjected to the 
usual tests, they exhibited satisfactory strength and 
ductility. 

In order to study this problem, two research proj- 
ects were initiated early in 1944: Project NRC-75 
(NS-306), Behavior of Steel under Conditions of 
Multiaxial Stresses and Effect of Welding and Tem- 
perature on this Behavior, at the University of Cali- 
fornia; and Project NRC-77 (NS-307), Behavior of 


CONFIDENTIAL 


104 


WELDING 


cleavage fractures of very low ductility occur, the 
fracture strength of the material is less than its yield 
strength. In the type of fracture encountered in 
welded ships, the yield strength has been raised ow- 
ing to the complex state of stress existing at the root 
of the fracture and the high strain rate. A method 
for separating these increments to the yield strength 
is not known. Subsequent investigations may show 
an equivalence between the effect of strain rate and 
state of stress on the yield strength comparable to 
the apparent relationship between strain rate and 
temperature. So far the explosion test appears to be 
the only method whereby strain rates of the order of 
those probably obtaining in ships during fracture 
can be achieved. 

Under Project NRC-72, Investigation of Factors 
Reducing the Effective Ductility of Welded Steel 
Members, at the Massachusetts Institute of Tech- 
nology, sufficient work has been completed to con- 
firm an apparent equivalence between temperature 
and strain rate recently promulgated.®^ This work 
was done using welded and unwelded-notched beam 
specimens, 1 in. by 1 in. by 6 in. in size, of several 
ship steels. The temperature was varied from -1-480 
to —280 F, and the testing speed to reach the yield 
point was varied from 0.05 second to 5 minutes. The 
investigation is being continued under the sponsor- 
ship of the Welding Research Council. 

The direct explosion test developed by the Trojan 
Powder Company under Project NRC-25 (OD-76) 
(NS-255), Direct Explosion Test for Welded Armor 
and Ship Plate (see also Sections 2.2 and 6.1.2), ap- 
pears to be a most promising method for determin- 
ing behavior of specimens, welded and unwelded, 
under high strain rates. Using plates approximately 1 2 
in. square, an essentially equal biaxial tensile stress 
can be produced on the tension face. This biaxial 
stress is accompanied by a third axial tensile com- 
ponent of unknown magnitude and phase relation- 
ship. Thus, it is possible to test plate specimens un- 
der triaxial stress and high strain rates and, in addi- 
tion, the temperature may be varied. Special explo- 
sives have been developed whereby the velocity of 
the detonating wave and the gas volume can be con- 
trolled. It is possible thereby to vary the shock load- 
ing so that the specimen can be fractured without 
spalling on the tension face. This was considered 
necessary, since it was desired to fracture the steel 
on planes normal to the plate surfaces, but at the 
same time keep the third-axis stress component as 


large as possible in order to maintain a high degree 
of restraint. Preliminary investigations have evalu- 
ated shipbuilding and HT steels in the same order 
as predicted by the Charpy impact test.®^^ Essentially 
the same results have been obtained from similar 
specimens subjected to a static-bend test at low tem- 
peratures.®^® 

This investigation is still in progress under a 
direct contract with the Bureau of Ships, Navy 
Department. 

6.2.6 Weldability of Hull Steel 

At the specific request of the Office of the Coordi- 
nator of Research and Development, Navy Depart- 
ment, two investigations, Project NRC-86 and Proj- 
ect NRC-87, were established in May 1944 to study 
the factors influencing the weldability of hull steels 
and to determine the relation between these factors 
and the metallurgical quality of the steels. 

Project NRC-86 (NS-255), Weldability of Steel 
for Hull Construction, at Lehigh University, utilized 
a restraint test which was found useful in predicting 
the behavior of steels and electrodes in the fabrica- 
tion of welded structures. Through this test, unde- 
sirable heats of HT hull steels could be segregated by 
determining their sensitivity to cracking when welded 
under various degrees of restraint.®^! The investiga- 
tion involved a study of such variables as the varia- 
tion of steel composition, variation of chemistry 
within a given specification, effect of position in 
the ingot, variation among steel suppliers for a given 
specification, effect of electrode, preheat, plate thick- 
ness, and edge preparation. 

This project made also a preliminary study®i® of 
the factors, such as metallurgical structure, tempera- 
ture, residual stresses, and stress concentration 
(notches), that are believed to affect the ductility of 
welded joints. The program included static-bend 
tests, notched and unnotched, in which the speci- 
mens were bent both longitudinally and transversely 
to the welds. An extensive investigation of the 
Charpy impact values at various positions in the 
weld heat-affected zone and parent plate was started 
in an attempt to explain the influence of each on 
the behavior of the plate as a whole in the bend test. 

Under Project NRC-87 (NS-255), Investigation of 
the Metallurgical Quality of Steels Used for Hull 
Construction, conducted by Battelle Memorial In- 


CONFIDENTIAL 


SHIP WELDING AND WELDED STEEL SHIPS 


105 


stitute, the factors influencing underbead cracking 
of HT steel were studied. A weld-bead test was de- 
veloped to measure this tendency. This test indicated 
large differences in crack sensitivity of various lots of 
the same grade of steel. Frequent variations of crack 
sensitivity were found that could not be explained 
on the basis of chemical analysis, end-quench hard- 
enability, hardness of the heat-affected zone or tensile 
properties. The crack sensitivities could be changed 
markedly by heat treatment. This investigation also 
included a study of the steel making and processing 
procedures used in making commercial heats of this 
giade of steel and involved the determination of 
crack sensitivity effects of plate thickness, position in 
the ingot, grain size, microstructure, and tensile 
properties.^12'^1^ 

Since these projects are being continued under di- 
rect contracts with the Bureau of Ships, Navy De- 
partment, only tentative conclusions can be drawn 
at this time. The following appear significant: 

1. Satisfactory correlation exists between the be- 
havior of four heats of HT steel as predicted by the 
restraint test^^^ and the direct explosion test.^®^ 
Both prime plate and double-V butt joints welded 
with E-6010 electrodes were tested. 

2. The transition temperature for the prime plate 
is lower than that for the welded plate in all cases 
where prime plate properties have been compared 
with welded plate properties in the as-welded con- 
dition by the static-bend test. The steel compositions 
investigated included a 0.18 carbon steel, a 0.25 car- 
bon killed steel, and an HT (0.18 per cent) carbon 
steel; the electrodes used included the E-6010, HTS, 
and 25-20 types. It is believed that this bend test can 
be used to determine the influences of such factors 
as metallurgical structure, dissolved gases, and re- 
sidual stresses on the ductilities of welded joints.^^^ 

3. The relative tendency toward underbead crack- 
ing of HT hull steel can be determined by a simple 
weld bead test made under closely controlled con- 
ditions.^i^'^^^ 

4. Higher compositions have generally greater 
sensitivity to underbead cracking. However, vari- 
ations in the crack sensitivity of different lots of HT 
steel occurred frequently. These variations could not 
be explained on the basis of chemical analyses, hard- 
enability, hardness in the heat-affected zone, or other 
properties commonly determined.^^^'^^^ 

5. Thermal treatment was indicated to have a 
pronounced effect on crack sensitivity. Homogeniz- 


ing decreases and annealing increases this sensitiv- 
ity 314,315 

6.2.7 Fatigue of Ship Welds 

On a number of ships, hairline cracks have been ob- 
served in the vicinity of the hatch corners. Owing to 
the stress concentration in this area occasioned by 
the hatch corner discontinuity, it appeared reason- 
able that these could be fatigue cracks caused by the 
alternating loads to which a ship is subjected in a 
seaway. These cracks would then propagate until 
the stress in this area had been lowered by the re- 
duction of the stress concentration factor. Upon sub- 
sequent loadings having higher stress amplitudes 
and increased strain rates, for instance, in a rough 
sea with a lowered temperature, it was expected that, 
owing to the lowered notch toughness, the hairline 
crack could act as a trigger to start a fracture prop- 
agating through the structure. 

Welded ships have suffered structural failures 
after only a short period of sea service or with no 
service at all. It appears, therefore, that while fa- 
tigue failure may be a contributing factor, it does 
not provide an adequate explanation for the struc- 
tural failures of welded ships. 

Project NRC-89 (NS-304), Fatigue Tests of Ship 
Welds, was established at Cornell University to de- 
termine the fatigue behavior of ship steel specimens 
containing longitudinal welds and cutouts with and 
without welded reinforcement plates and doublers. 
No significant conclusions can be drawn as yet ow- 
ing to the limited amount of work completed.^^® 
This investigation is being continued under a direct 
contract with the Bureau of Ships, Navy Depart- 
ment. 


* Status of the Research Program 

Since most of the above-mentioned investigations 
are still in progress under the sponsorship of the 
Bureau of Ships, Navy Department, no evaluation 
of the results can be given at this time. However, it 
appears reasonable to anticipate that the completion 
of these projects will assist in determining the rela- 
tive importance of the design, material, and fabrica- 
tion method in the successful service performance of 
welded ships. Thus, it is anticipated that the results 


CONFIDENTIAL 


106 


WELDING 


of this research program will ultimately be of con- 
siderable assistance in the design and construction of 
low-cost welded ships of assured service performance. 
This background information will be of particular 
value in the future construction of welded passenger 
ships where even minor structural failures may have 
most serious consequences. 

Most of the Division 18 projects, which have been 
taken over under direct contracts by the Navy De- 
partment, are being continued for the present under 
the supervision of the War Metallurgy Committee. 
The objective of these projects is to obtain addi- 
tional experimental data upon which definite rec- 
ommendations bearing on the problem of the design 
and construction of welded ships can be based. This 
work will involve: 

1. Obtaining additional data to explain more 
fully the reasons for the reduction of the strength 
and ductility of welded structures, especially at low 
temperatures or high-strain rates, by means of (a) 


investigations of the large as-welded tubes (20 in. in 
diameter, ^-in. wall) subjected to biaxial tensile 
stresses, especially when tested at low temperature 
(—40 F), and (b) bend tests of unnotched plates con- 
taining a butt weld or surface weld bead and sub- 
jected to the explosion test or a static-bend test at 
low temperature. 

2. Performing additional tests on steels of supe- 
rior notch toughness using large flat plate and hatch 
corner specimens. 

3. Investigating improved hatch corner designs. 

4. Continuing the investigation to determine the 
fracture stress at zero ductility of steel in an attempt 
to explain the factors, particularly from the view- 
point of metallurgy and mechanics, which control 
the change from shear to cleavage type fractures. 

5. Attempting to develop a laboratory test to pre- 
dict the service performance of large structures. 

6. Obtaining information relative to the fatigue 
behavior of typical ship welds. 


CONFIDENTIAL 


Chapter 7 

FOUNDRY MATERIALS AND PROCESSES 


7.1 MALLEABLE IRON 


E arly in World War II steel-making facilities were 
often overloaded with orders for cast steel prod- 
ucts as the demand far exceeded the capacities of the 
industry. It became apparent that, if malleable iron 
could be used in war material applications where 
steel had been used, the large productive capacity of 
the malleable iron industry would be available to the 
war effort. 

When substitution of malleable iron for cast steel 
in tanks, combat vehicles, and other military applica- 
tions is contemplated, a question arises as to its 
behavior at low temperatures and at elevated tem- 
peratures. While experience in other uses indicates 
that, over the range of temperature involved, malle- 
able iron does not depart greatly from its room-tem- 
perature behavior, more information was needed. 
To explore this possibility, the Ordnance Depart- 
ment requested, under their control number OD-81, 
that the effects of temperature on the properties of 
malleable iron be investigated. Therefore, Project 
NRC-28, Properties of Malleable Iron Castings for 
the Use in Tanks, Combat Vehicles, and Other 
Military Applications, was established at Battelle 
Memorial Institute. This project encompassed an 
investigation of the effects of low temperatures on 
the impact resistance of malleable iron castings by 
Charpy impact, tensile impact, and wedge tests on 
different grades of commercial malleable irons, pearl- 
itic malleable irons, and cupola malleable irons over 
a temperature range from +75 to —50 F, and a study 
of the effects of elevated temperatures on the same 
variety of malleable irons by the same tests at tem- 
peratures up to and including 1200 F. 

A comparison of the mechanical properties of or- 
dinary grade B cast steel, normalized and drawn, 
with those of malleable irons, heat treated according 
to their class, is given in the following tabulation: 


Grade B 
cast steel 

Yield strength, psi 45,000- 

55,000 
(0.2 per 
cent offset) 

Tensile strength, psi 75,000- 

90,000 


Malleable iron 


Regular 

Pearlitic 

Cupola 

33,000- 

42,000- 

25,000- 

37,000 

57,000 

30,000 

53,000- 

75,000- 

42,000- 

57,000 

93,000 

48,000 


Malleable iron 

Grade B Regular Pearlitic Cupola 
cast steel ® ^ 


Elongation, per cent 

25-35 

121/2-25 

8-18 

5-7 

Reduction of area. 

per cent 

30-55 

20-25 

5-15 

4-7 

Charpy impact (room 

temp.) keyhole, ft-lb 

15-30 

5-8 

2-6 

4-5 

Charpy impact (—40 F) 

1-20 

3-7 

1-3 

3-4 


Regular malleable is peculiar in that increased 
strength and increased ductility go hand-in-hand. 
With other ductile ferrous products, ductility de- 
creases as strength increases. 

Pearlitic malleable can be made with a yield 
strength closely approaching that of cast steel, but it 
has lower ductility. Regular malleable runs below 
cast steel in both yield strength and ductility, but, if 
the design in which substitution is to be made does 
not require all the yield strength of steel, or if the 
design is modified in accordance with the yield 
strength, it should be a usable material, for it com- 
bines a fair level of toughness and has long been used 
in many severe services, e.g., in railway parts and in 
trucks where it may have to resist shock and even bat- 
tering. Cupola malleable, though made more eco- 
nomically than the other types, has a relatively low 
level of strength and ductility, although it serves well 
for some purposes, such as pipe fittings. All the mal- 
leables, especially regular malleables, are very readily 
machined having, in this respect, a material practical 
advantage over cast steel. 

When comparing malleable with cast steel with 
respect to low-temperature behavior, it needs to be 
recalled that cast steel may show very low notched 
bar impact values at low temperature, as the cited 
range of 1 to 20 ft-lb at -40 F shows. 

It is now well understood that within this range 
variations in cast steel are governed by the deoxida- 
tion practice. Thus, well deoxidized basic or acid 
open-hearth, basic or acid electric, and converter 
steels will give results hugging the top of the range. 
Poorly deoxidized steels made by any of these proc- 
esses may hug the bottom of the range. 

Not much attention has been paid to this, and 
much cast steel with very low notched bar impact 
resistance at subnormal temperatures has un- 
doubtedly been in low-temperature service and given 
satisfactory service under conditions where the 


CONFIDENTIAL 


107 


108 


FOUNDRY MATERIALS AND PROCESSES 


designer, had he appreciated how brittle poorly made 
cast steel can be at low temperature, would have 
specified that the steel be tested for low-temperature 
toughness and that those heats of steels lacking in 
such toughness be rejected. That is, cast steels no 
more resistant to shock at low temperature in the 
presence of notches than the better grades of malle- 
able, have given useful service. Neither steel nor mal- 
leable parts that are too severely notched will stand 
severe impact. Engineering design has to recognize 
this and see to it that where impact is involved 
severe notches are absent, and that where notches 
cannot be avoided the parts are protected from re- 
ceiving severe shock by design of the assembly. 

It is well known that the usually determined me- 
chanical properties of both steel and malleable, with 
the exception of notch toughness or impact resist- 
ance, improve as the temperature drops within 
atmospheric temperature limits. Attention was 
focused, therefore, on the low-temperature impact 
behavior. 

Tensile impact results on unnotched bars of all 
three types of malleable do not materially diverge, 
either in energy absorbed or in elongation produced, 
from room-temperature results, even down to —80 F. 
At least down to —40 F, the same was true of un- 
notched Charpy bars. 

Cupola malleable did not prove promising for 
low-temperature use. Pearlitic malleable was some- 
what more promising in view of its high yield 
strength, with fair low-temperature behavior, but 
regular malleable showed the best low-temperature 
behavior. 

However, regular malleable should be so heat 
treated as to remove all vestiges of pearlite. 

Notched bar impact tests are not so selective as the 
wedge-curl drop test, and wedge-curl drop tests at 
low temperatures seem indicated for proving that the 
heat and heat treatment have produced material that 
will be tough at low temperatures. If such testing is 
applied to eliminate material of doubtful quality, 
regular malleable can be selected that appears to have 
as good toughness at —40 F as at room temperature, 
and usable toughness at still lower temperatures. 

At elevated temperatures, the best combination of 
properties in all irons occurred in the temperature 
range of 70 to 200 F. Above these temperatures and 
up to about 600 F, ductility either remained con- 
stant or fell off. Charpy impact values fell off con- 
tinuously to about 1000 F, while wedge test results 


generally reached a low point at temperatures rang- 
ing from 400 to 800 F. Tensile impact values dropped 
steadily to about 800 F and the strength held up fairly 
well to 600 F, above which it dropped off rapidly 
while the ductility correspondingly increased. 

The results of this investigation provided 
data^i^’*'^^® upon which the substitution of malleable 
iron for cast steel could be based in considering mate- 
rials for various parts of war material in the expecta- 
tion that such would divert a considerable tonnage 
from steel to the more plentiful malleable iron facil- 
ities. A summary of this work was published serially 
for the benefit of industry.-^^^ 

7 2 CENTRIFUGAL CASTING 

Survey of the Status of Centrifugal 
Casting 

As malleable iron was substituted for cast steel in 
order to alleviate shortages in steel casting facilities, 
it was believed that castings, particularly steel cast- 
ings, made by the centrifugal casting process might 
to some extent replace forgings and thus relieve the 
pressure on forging facilities. Conventional mass 
production facilities for the manufacture of forg- 
ings and seamless tubings were inadequate to meet 
the unusual demand and, because of the relatively 
small initial investment, centrifugal casting methods 
appeared attractive and promising. To determine 
the feasibility of this substitution, the War Metal- 
lurgy Committee carried out a survey of the status 
of development of the centrifugal casting process 
and of the possibility of extending its use to items 
of ordnance materiel. The applications, advantages, 
and limitations of the process were studied and, al- 
though the survey was not complete, it was adequate 
for the purpose of appraising the general problem 
and providing a basis for the formulation of a pro- 
gram of development. In the report on this sur- 
yey,32o f^yg immediate needs were indicated and four 
projects were established. Subsequently, the Army 
Ordnance assumed active sponsorship of these proj- 
ects under their control number OD-108. 


Bibliography on Centrifugal Casting 

This bibliography'^-i was prepared by the Naval 
Research Laboratory under Project NRC-34N (OD- 


CONFIDENTIAL 


CENTRIFUGAL CASTING 


109 


108) in cooperation with the War Metallurgy Com- 
mittee. The report consists of a short resume of the 
centrifugal casting field, a discussion of the funda- 
mentals of the various processes, brief abstracts of 
the more comprehensive writings on the subject, and 
a chronological, classified listing of publications and 
patents. It provided assistance not only to the groups 
engaged in centrifugal casting but also to those con- 
templating entering the field. 

’•2*3 Heat Flow in Metal Molds 

As recommended by the survey. Project NRC-33 
(OD-108), Analysis of Heat Flow in Metal Molds 
for Centrifugal Casting of Gun Tubes, Airplane 
Cylinders, Tank Bogey Wheels, and Other War Ma- 
teriel, was established at Battelle Memorial Institute 
with the objective of obtaining data which would 
permit improved designs of casting machines, in- 
creased life of molds, and improvements in cast 
product owing to accelerated and controlled heat 
abstraction. 

The adoption of centrifugal casting in metal molds 
for production of steel gun tubes, aircraft engine cyl- 
inders, tank bogey wheels, etc., raises questions as to 
the proper material for molds and the proper thick- 
ness of the molds. 

Molds could be made, for example, of steel, cast 
iron, or copper, with the first cost and ease of manu- 
facture naturally in favor of cast iron. The molds 
can be thin or thick, with first cost and ease of spin- 
ning on the side of thin molds. The outside can 
be plain or corrugated and can be air cooled or 
water cooled. 

Failure of molds usually occurs by heat checking, 
a result of repeated tensile stresses. The number of 
casts before a mold has to be discarded because of 
heat checking depends upon the magnitude of the 
tensile stress set up by the thermal gradient and upon 
the ability of the material to withstand repeated ten- 
sile stresses of that magnitude. 

Fundamental information on the thermal gra- 
dients and resulting stresses was sought by elaborate 
experiments on steel, cast iron, and copper slabs of 
different thicknesses, cooled in various ways, when 
varying amounts of molten steel were cast upon 
them. 

The results ''^22 showed that the stresses produced 
in the different materials are pretty much at the 


same level as their known ability to resist repeated 
stresses. This results from the differences in modulus 
of elasticity among the three materials. Water cool- 
ing does not seem to offer much advantage over air 
cooling. 

Since the other materials do not appear outstand- 
ingly better than cast iron, the commercial use of 
cast iron for molds seems justified. While thin molds 
reach maximum temperature and maximum stress 
quicker than thick ones, thus giving less time for 
stress relief, the overall service, compared with cost, 
will probably be better for thin molds than for thick 
ones. 

Marked improvement by lowering maximum tem- 
perature and maximum stress is afforded by a heat- 
insulating mold coating 0.04 in. thick. A coating 
of 0.01 in. in thickness is much less effective. Rather 
thin, air-cooled, cast iron molds with the 0.04-in. 
insulating coating appear at least as good an engi- 
neering choice as any other readily available mold 
material. 

7.2.4 Mathematics Underlying the Process 

Survey Project SP-10 (OD-108), Mathematics Un- 
derlying the Centrifugal Casting of Metals, was car- 
ried out by the War Metallurgy Committee, and the 
report was edited and revised by the Applied Math- 
ematics Panel of the NDRC. 

Centrifugal casting, not only of cylindrical objects 
but also of other shapes, involves forcing molten 
metal under pressure against the mold wall by 
centrifugal force. The pressure is usually expressed as 
“times gravity.” The optimum pressure for any given 
setup is produced at some particular rotational speed. 
Mold inside diameter, casting thickness, density of 
metal being cast, rotational speed, and angle of in- 
clination of the mold to the horizontal all enter as 
variables. It is premature to assume that an ideal 
rotational speed can at present be calculated or pre- 
dicted because of the many variables concurrently 
operating and the lack of knowledge regarding the 
interrelationship of these variables. The report on 
the project^23 does, however, present information on 
the mathematics underlying the mechanics of metal 
spinning and is a practical manual by which the 
more obvious values of practical interest, such as 
times gravity and pressure on mold wall, can be de- 
termined and converted from one to the other by 


CONFIDENTIAL 


110 


FOUNDRY MATERIALS AND PROCESSES 


means of handy charts. It also provides a common 
nomenclature for the use of those contemplating the 
adoption of the process. 

7.2.5 Development and Extension of 
Centrifugal Casting Methods 

Project NRC-26 (OD-108), Improvements in and 
Extension of Centrifugal Casting Methods for Pro- 
duction of Miscellaneous War Materiel Items, was 
established in the laboratories of the United States 
Pipe and Foundry Company. It involved applica- 
tion of centrifugal casting methods to objects ordi- 
narily produced by other methods, but for which 
methods existing facilities were limited. 

Seamless steel tubing was not in sufficient supply 
to provide the desired number of 60-mm trench mor- 
tar barrels and, at the request of the Philadelphia 
Ordnance District, centrifugal casting of such mor- 
tar barrels was studied.^^r Casting centrifugally in a 
steel mold preheated to about 350 F and sprayed 
with a water suspension of silica flour and colloidal 
bentonite produced tubes which, after rough ma- 
chining, were free from visible defects and withstood 
the hydraulic pressure test. Heat-treated and ma- 
chined, such tubes were found entirely satisfactory 
on overload proof-firing tests at Aberdeen Proving 
Ground. Casting details as to mold speed, mold tem- 
perature, refractory coating thickness, casting tem- 
perature, speed of pouring, etc., were then worked 
out. 

The process was applied to the commercial pro- 
duction of 60-mm and 81-mm trench mortar barrels. 
This released for production of aircraft tubing the 
equipment for making seamless tubing that would 
otherwise have been required for trench mortar 
barrels. The cost of the centrifugally cast barrel is 
higher but production facilities, rather than cost, 
were the important feature of the situation that was 
thus met. 

The success of this work led to a study of the cast- 
ing of recoil cylinders for90-mm and 105-mm guns'^^^ 
at the request of the Army Ordnance Department. 
These large castings, over 5 ft long, 6 in. OD, and 
3 1/2 in. ID in the rough, were made in cast iron 
rather than steel molds, carrying a refractory wash. 
Machining i/^ in. each from the OD and ID removed 
all casting defects and shrinkage, and recoil cylinders 
from the castings, after heat treatment, finish ma- 


chining, honing and lapping, met all requirements 
of mechanical properties, machinability, and finish- 
ability. 

Rock Island Arsenal reported^24 these centrifu- 
gally cast recoil cylinders as follows. 

1. The ten (lo) centrifugally cast cylinders submitted by 
the U. S, Pipe and Foundry Company, Burlington, N. J., have 
been found to be suitable for processing into 105-mm recoil 
cylinders which meet all requirements and specifications, in- 
cluding physical properties, machining, honing, and lapping 
characteristics. 

2. It is believed that, if cylinders can be produced by cen- 
trifugal casting which consistently show composition and phys- 
ical characteristics similar to the ten (10) cylinders tested, an 
additional source of cylinder stock, other than those of bar 
stock and drawn tubing, can be developed by the method of 
centrifugal casting. 

An attempt was made to produce steel recoil cyl- 
inders lined with monel metal to replace those made 
from solid forgings of monel. ^^5 This would have 
saved much critical monel metal. No successful bond- 
ing was accomplished by centrifugally casting monel 
metal into a heated steel tube, but good bonding 
was produced by pouring molten steel into the ro- 
tating mold first and following this, while the steel 
was still above 2500 F, with a pour of molten monel 
metal. Unfortunately, shrinkage voids in the monel 
metal produced small imperfections in the ID not 
permissible in recoil cylinders. As the use of monel 
metal for recoil cylinders had been abandoned by 
the time satisfactory bonding had been achieved, the 
problem no longer existed and no further attempt 
was made to produce duplex steel-monel castings 
with perfect interiors. 

End connections for tank treads were cast^-^’^^^* 
using several molds arranged radially about a cen- 
tral pouring gate, and using special dry sand mixes 
to avoid cutting the mold by the molten metal. Cen- 
trifugal force was used to flow the molten metal into 
the molds. After working out the proper gating, 
radiographically sound castings were made and sup- 
plied to the Army Ordnance Department for heat 
treatment and service test. Early fracture of some of 
the castings brought out the fact that the heat treat- 
ment applied by the Ordnance Department was 
quenching without tempering, the Brinell hardness 
being 500 instead of the specified 330 to 375. The 
Army Ordnance Department planned to temper the 
castings properly and run them to destruction, but 
apparently this was never done because adequate forg- 
ing facilities had been provided by that time. From 
the analogy of other cases, one would expect that, had 
the test been made, the centrifugal castings, correctly 


CONFIDENTIAL 


PRECISION CASTING 


111 


heat treated, would have proved serviceable. 

X4130 steel for seamless tubing for aircraft is nor- 
mally cast into ingots, rolled to blooms, the blooms 
reheated and rolled into rounds, and the rounds 
pierced in a tube mill. All this processing to produce 
a hollow round for subsequent rolling and drawing 
could be obviated by centrifugal casting of a hol- 
low round billet in the first place. This was 
done-^25,326 and the centrifugal billets hot rolled and 
drawn. No difficulty was met in these operations. 

However, no boring or broaching was done on the 
ID of these hollow cylinders, that is, no removal was 
made of the last metal to freeze. There was no analog 
of the cropping of an ingot. As a result of shrinkage 
voids distributed over the ID of the casting, the in- 
side of the finished tube contained imperfections not 
permissible in aircraft tubing. 

Quite the same condition was met in a similar 
effort to produce blanks for ball-bearing races by cen- 
trifugal casting of alloy 52100.'^^® Such cast blanks 
were cold reduced with equal facility to the hot- 
rolled tubing ordinarily used, but, since the ID was 
not machined, flaws similar to those noted above 
appeared on the ID of the finished race, and the 
material was not acceptable. 

In these particular cases, lack of suitable facilities 
for cleaning up the ID led to abandonment of the 
centrifugal casting method, though with such a clean- 
ing-up operation there is reason to expect that the 
serviceable castings might have been produced. 

All these experiences show that it is futile to ex- 
pect perfect ID on centrifugally cast tubes when no 
one would expect to use an ingot without cropping 
off the piped top. The piping shrinkage that results 
from the volume change in going from the liquid to 
the solid has to take place. In the centrifugal casting 
it takes place all over the ID and the resulting un- 
sound inner surface has to be removed from any such 
casting where a sound ID is needed, just as it is re- 
moved from centrifugally cast guns. In cases where 
such removal is done, as in centrifugally cast guns, 
centrifugally cast tubes are capable of giving high- 
quality metal. 

An effort to produce a duplex metal casting of 
steel within copper, for the purpose of conserving 
copper in driving bands for shells, proved unsuc- 
cessful.326 The steel solidifies first and undergoes its 
normal shrinkage while the surrounding copper is 
still molten along the interface. Centrifugal force 
then acts to separate the two metals rather than to 


bring them together. Duplex driving bands are dis- 
cussed also in Chapter 5 of this report. 

The progress reports cited in the foregoing give 
all details of the investigation while the final re- 
port327 summarizes the work. 

’•2 6 Commercial Application of the 
Process 

Correlation Project NRC-61A, Experimental Pro- 
duction of Pilot Static and Centrifugal Castings for 
the Armed Services, which was financed and con- 
ducted by the American Brake Shoe Company under 
the general supervision of the War Metallurgy 
Committee, was a study of the application of the 
centrifugal casting process to the manufacture of 
composite grinding rolls.^^-® In this investigation, 
techniques were developed, much operation data 
were obtained, and practices were recommended. 
Also studied under this project were the differences 
in the fluidity of various commercial grades of heat- 
resisting alloys. An improved method was developed 
for evaluating fluidity by the cast spiral technique.-"^-^ 

7 3 PRECISION CASTING 

As a result of a number of informal suggestions 
from the Armed Services and the War Production 
Board as to the need for a general and rather elemen- 
tary review of the field of precision casting of metals, 
the War Metallurgy Committee carried out Survey 
Project SP-14, Centrifugal and Precision Casting of 
Nonferrous Alloys. The report on this project^^^ 
described the various methods of casting metals, and 
was intended for those having little or no experience 
in the field of precision casting, who might be urged 
to consider the production of such castings to ease 
the demand on forging and machining facilities. 
The portions of this report relating specifically to 
the so-called lost wax precision casting process were 
duplicated by OPRD and widely distributed to in- 
dustrial concerns. 

The above-described survey indicated the desira- 
bility of further study of precision casting methods 
so that they could be applied to the production of 
war materiel, such as intricate parts for artillery and 
small arms firing mechanisms, parts for breech mech- 
anisms, rocket nozzles, and other urgently needed 
parts made from commercial structural steels ur- 


CONFIDENTIAL 


112 


FOUNDRY MATERIALS AND PROCESSES 


gently needed, but the production of which was 
hampered by the lack of machine tool capacity and 
the need for an excessive amount of hand work. The 
precision casting process also held promise for the 
production of alloy metal parts from materials not 
forgeable or machinable. Project NRC-69, Develop- 
ment and Extension of Precision Casting Methods 
for Production of Miscellaneous War Materiel Items, 
was established in the research laboratories of the 
General Electric Company because that company 
was one of the pioneers in the field of precision cast- 
ing. Subsequently, the Army Ordnance Department 
assumed the sponsorship of the project under con- 
trol number OD-144. 

Dentists and jewelers have long been accustomed 
to making small castings of precious metals to very 
precise dimensions. A model is made in wax, coated 
with a wash that will give a smooth surface on the 
final casting, and “invested” in a refractory material. 
The wax is melted out, and the metal cast into the 
space formerly occupied by the wax. This is the so- 
called lost wax process which had been used by the 
ancient Greeks in making statuary. 

The dentist uses this method not because his alloys 
could not be formed in other ways, but merely be- 
cause it is the simplest way of making just one object 
of particular dimensions and contour. However, the 
process also serves for production of repetition cast- 
ings, very close to size, of alloys that cannot be forged 
or machined, and which would be difficult to cast to 
required dimensional tolerance by more common 
foundry methods. It will produce, with even better 
dimensional certainty than die casting, castings from 
alloys of such high melting point that they cannot 
be die cast. It has been especially valuable in the 
production of supercharger buckets from special 
heat-resisting alloys, difficult or impossible to forge 
or machine. 

In production of such parts by the millions, in- 
stead of modeling the wax pattern for each casting 
as is done when only one casting is to be inside, many 
wax patterns, exact duplicates of each other, have to 
be prepared. Hence, a master pattern is constructed 
and from this a mold of soft, low-melting alloy is 
made. Into this mold is forced a suitable wax, using 
injection molding methods, such as are employed in 
molding plastics. 

One or more of the wax patterns so made, coated 
with a fine-grained precoat, are surrounded with a suit- 
able refractory slurry, which sets up to a hard mass. 


The wax is then melted out, the mold suitably pre- 
heated, and the metal to be cast poured into the mold, 
sometimes being forced in by air pressure, sometimes 
centrifugally as in common dental practice. 

While these steps sound simple, it should be noted 
that (1) the wax pattern is warm and expanded when 
formed, but cold when surrounded with investment, 
and (2) the refractory mold expands when heated, 
and the final casting contracts on cooling. All these 
thermal dimensional changes have to be allowed for, 
each material used in the sequence of operations 
must be suitably chosen, and the gating of the wax 
pattern must be so designed that the wax will melt 
out cleanly and the casting be properly fed so as to be 
sound. Thus, many important steps have to be worked 
out for each particular case. Once they are worked 
out, castings can be produced with marvelous pre- 
cision of dimensions, often requiring no finishing 
other than removing gates, and perhaps buffing. 

Obviously, the difficulties increase as the size of 
the piece increases. Small turbine blades of alloys 
difficult to form by other methods and several small 
gun parts of ordinary steels requiring very close di- 
mensions and costly machining account for much 
of the production. Under either of these conditions 
the process is economical, although it would seldom 
be economical for parts easily made by other proc- 
esses or not requiring extreme closeness of dimen- 
sions. Somewhat analogous methods, using plaster 
molds, are used for certain brass or aluminum cast- 
ings, in which high, but not extreme, dimensional 
precision is required. 

Each object to be made by precision casting is a 
problem in itself and has to be studied as such. Part 
I of the final report on the project^^^ describes in 
rather general terms the fundamentals of the proc- 
ess and the various steps used in precision casting, 
particularly in the casting of ferrous and higher 
melting nonferrous alloys. Some of the parts made 
were cast rocket jets, cast gun parts, and escort vessel 
turbine valves. The General Electric Company also 
instructed personnel of several commercial concerns 
and governmental agencies in the art of making pre- 
cision castings. Part II of the final reporU32 briefly 
describes the achievements of the organizations that 
were instructed in precision casting methods through 
the activities of the project. The experience of 
Watervliet Arsenal in making precision-cast gun 
parts is reviewed and the cost data indicative of the 
savings affected through the use of the process are 


CONFIDENTIAL 


REFRACTORIES 


13 


given. It is noteworthy that the precision-cast gun 
parts not only had properties equal or superior to 
those manufactured by conventional machining or 
forging operations, but also were manufactured at 
a considerably lower cost. For example, a trigger of 
SAE 3415 steel costs $8.33 when made by machining 
methods and but $1.69 when made by precision cast- 
ing methods and finished. Other comparisons were 
less striking, but in all examples cited the saving 
amounted to more than 30 per cent. 

Part II of the final report'^^^ on Project NRC-61A, 
Experimental Production of Pilot Static and Cen- 
trifugal Castings for the Armed Services, gives a 
realistic and detailed account of the difficulties met, 
of how some were overcome, and of the logical steps 
for overcoming the others, in making gas turbine 
diaphragms by a modification of the precision cast- 
ing method. This report gives considerable insight 
into the process and is commended to those who are 
concerned with the production of large, heavy, and 
intricate castings. 

74 REFRACTORIES 

Investigation of two refractory problems was un- 
dertaken by the former Division B, NDRC, at the 
request of Watertown Arsenal. These problems in- 
volved the development of a substitute for sillima- 
nite and studies of pouring box refractories. The 
projects were established prior to the outbreak of 
World War II and their supervision was transferred 
from Division B, NDRC, to the Metallurgical Ad- 
visory Committee of the National Research Council 
(later the War Metallurgy Committee) in March 
1942. The work was completed shortly thereafter. 

Substitute for Sillimanite 

Project B-95 (OD-35-2), Development of Substitute 
for Sillimanite in Pouring Rings Used in Special 


Steel Foundry Practice, was conducted by the Massa- 
chusetts Institute of Technology. The objective of 
the investigation was to develop a substitute for 
sillimanite, or Indian kyanite, because of their scar- 
city due to unsettled world conditions. It was found 
that a kaolin grog-clay-sodium silicate mixture, all 
domestic materials, was a suitable substitute refrac- 
tory for pouring rings, although there was no assur- 
ance that the mixture would be suitable for other 
refractory purposes. The mixture was proved satis- 
factory in ramming and casting operations at Water- 
town Arsenal. ^34, .H35 addition to this develop- 

ment, a mold was designed for the mechanical 
pressing of the pouring rings. Trials made using this 
method indicated that a large amount of time and 
labor could be saved in molding as well as accom- 
plishing considerable improvement in the quality 
of the finished pouring rings.^'^'’ 

7.4.2 Pouring Box Refractories 

Project B-103 (OD-35-1), Acceptance Test for Fire- 
brick: Pouring Box Refractories, was carried out by 
Ohio State University. The objective of this investi- 
gation was to develop a rapid acceptance test method 
for fire clay brick to be used at Watertown Arsenal 
in pouring boxes for handling molten steel where 
the brick must endure high thermal shock. Under 
the project a simple slag penetration test was devel- 
oped. This involved studies of the properties of the 
refractories used, the design, construction, and opera- 
tion of a slag test furnace, and the correlation of 
the test results with the experience of Watertown 
Arsenal in the behavior of the various refractories 
used. The work was done with the active cooperation 
of Watertown Arsenal and sufficient data were ob- 
tained for the preparation of specifications for pour- 
ing box refractories.3^®’^^7 


CONFIDENTIAL 


Chapter 8 

EXAMINATION OF ENEMY MATERIEL 


T he research and development program of the 
Armed Services required an intimate knowledge 
of enemy materiel. Early in World War II the War 
and Navy Departments organized specialized groups 
to study captured equipment in the field and to 
secure representative samples for more complete ex- 
amination in this country. Collection centers were 
established at Aberdeen Proving Ground by the 
Office of the Chief of Ordnance, War Department, 
and later at Anacostia by the Office of the Chief of 
Naval Operations, Navy Department. Equipment 
was tested functionally at these centers or sent to 
the service laboratories or the arsenals for more 
complete examination. 

After functional tests were completed, it was fre- 
quently desired to know more about the materials 
and manufacturing methods used by the enemy than 
could be secured conveniently by the service labora- 
tories. It was recognized that civilian research lab- 
oratories and civilian metallurgists, chemists, and 
engineers who had broad familiarity with produc- 
tion methods could be used to advantage to supple- 
ment the service organizations in securing the de- 
tailed information needed to establish trends in 
development projects and in the use of materials. 

This type of information was also needed by the 
Board of Economic Warfare to follow the economic 
aspects of the changing materials situations in the 
enemy countries. 

Accordingly, after consultation with the Army 
Ordnance Department, the Board of Economic 
Warfare (later the Foreign Economic Administra- 
tion), members of the War Metallurgy Committee, 
and investigators of the Division 18 projects on 
armor plate, gun steels, and other materials of war, 
it was recommended that a project be established 
for the examination of enemy materiel as part of the 
research program of Division 18. 

The project was established at Battelle Memorial 
Institute as Project NRC-32 in September 1942. Sub- 
sequently, the Army Ordnance Department, the 
Army Air Forces, and the Navy Department en- 
dorsed the project through channels assigning their 
control numbers OD-113, AC-77, and N-119, respec- 
tively. A project committee was appointed by the 


War Metallurgy Committee to advise in the selec- 
tion and examination of materiel. 

Items of captured materiel were selected by the 
project committee to provide information for Divi- 
sion 18 NDRC research projects as well as the War 
and Navy Departments, the Foreign Economic Ad- 
ministration, and the Office of Strategic Services. 
Most of the selections were made after consultation 
with the interested branch of the Armed Services, 
while some of the items were selected by the Services 
and shipped to Battelle Memorial Institute for ex- 
amination. 

The project was organized to use the specialized 
knowledge and facilities of the various laboratories 
and industries anywhere in this country as might be 
indicated by the particular item under study.^ 

The purposes of the project were, first, to find 
whether the enemies had improved compositions or 
fabrication practices and second, to note the progress 
of the conservation measures they adopted to combat 
raw material shortages. 

The work dovetailed into that of the Armed Serv- 
ices and of the British. At the beginning it was 
chiefly on German projectiles and small arms with- 
out much attention to German aircraft, since the 
British were reporting on that. Later, some large 
German guns were studied. As Japanese materiel 
became available, the proportion of specimens of 
Japanese origin sent in by the Services increased. 
Japanese airframes and aircraft engines came in in 
considerable numbers. Aircraft instruments from 
both Japanese and German planes were also sup- 
plied. Periodic trips were made to collection centers 
to select informative specimens. When possible, se- 
lections of materiel for examination were made of 
chronological series of items to show changes indi- 

a Organizations working on this project included; 

Alnminnm Company of America, Bendix Aviation Corpora- 
tion Scintilla Division, Bendix Aviation Corporation Eclipse 
Aviation Division, Bethlehem Steel Corporation, Chrysler 
Corporation, Ethyl Corporation, Forest Products Laboratory, 
General Motors Corporation, Goodyear Tire and Rubber 
Company, Indiana Steel Products Company, The Massachusetts 
Institute of Technology, Mellon Institute, National Cash 
Register Company, The New Jersey Zinc Company, V. L. 
Smithers Laboratories, A. O. Smith Corporation, John A. 
Roebling Sons Company, Rome Cable Corporation, Wallace 
Barnes Company, Western Cartridge Company, and Wyman 
Gordon Company. 


II4 


GONFIDEN UAL 


EXAMINATION OF ENEMY MATERIEL 


115 


eating material shortages as well as possible trends 
in development. 

The Services first examined the available materiel 
for its functioning and behavior before turning it 
over for study of material and fabrication, unless 
plenty of duplicates were available. Some articles of 
prime and immediate interest were at once exam- 
ined as to material by the Services. The role of this 
project was to supplement such examinations and 
fill in gaps, so that a chronological history of enemy 
materials and fabrication practices might be built 
up, insofar as materiel of known dates of manufac- 
ture were at hand. 

It was not expected that much of a startling nature 
or many striking innovations would turn up, for 
metallurgical practice is necessarily pretty much 
alike the world over, but it was considered necessary 
to watch for any such cases that might occur. Few 
cases were met where the enemy appeared to have 
anything different and worth copying. These were 
promptly followed up by the Services. 

On the whole, the picture showed adoption by the 
Germans of chromium and manganese steels for 
heat-treated parts of heavy sections for vital service, 
with every possible economy in use of nickel. This 
development reflected the German supply problem 
and underlined the correctness of the program of 
strategic bombing and diplomatic and economic ac- 
tion to pinch off the supplies of chromium and man- 
ganese. The German shortage of copper also was 
very apparent. 

As the war went on, the German products showed 
somewhat increased use of free-machining steels and 
labor-saving practices, though assemblies that would 
here be made from stampings by copper brazing or 
welding were still made by more laborious methods, 
and the application of free-machining steels was still 
astonishingly small. 

German foundry practice, on both steel and alu- 
minum alloys, was evidenced to be excellent. Ma- 
chine work as to tolerances and finish was uniformly 
good. In general, the German implements of warfare 
were made from available materials so chosen and 
so processed that the implements were effective for 
their purposes. German technology produced reli- 
able planes, guns, projectiles, and armor. Where 
their practice deviated from ours, it was usually 
with a purpose. Their armor welding was poor by 
our standards, but their tank design did not depend 
so much on the integrity of the weld as does ours. 


They made more consistent use of steel cartridge 
cases than we, being forced to this by the copper 
shortage. Their use of porous iron driving bands, 
probably motivated at first by the copper shortage, 
was probably accelerated by an even more satisfac- 
tory performance of the bands than they expected. 

These bands are very brittle by ordinary tests but 
do not act brittle under the stresses imposed on them 
in service. The porous iron band deserves more at- 
tention than it has had here, especially from the 
point of view of duplicating the porosity and not 
trying to make a band of the greatest possible solid- 
ity. The Germans used some solid, soft iron bands 
but soon found the porous band preferable. 

The Japanese products showed little variance from 
the old, established prewar choices of materials. 
Probably because of the availability of Chinese tung- 
sten, some of their heat-treated steels utilized tung- 
sten as an alloying element, but in general their 
choice of materials reflected German practice of 
about 1930 and even went beyond it in lavish use 
of nickel. 

In some cases the materials and processing were 
exact duplicates of those used in German or Ameri- 
can products which they were copying as to design. 

The raw materials classed as strategic or critical 
in the United States and even more in Germany were 
used by the Japanese without stint, so lavishly as to 
suggest that huge stock piles of raw materials and 
alloying elements, especially copper and nickel, had 
been accumulated and were being drawn upon with- 
out thought of conservation. In a few instances of 
late 1943 or 1944 manufacture, aircraft engine parts, 
previously high in nickel, were of low nickel or 
nickel-free steels with chromium and manganese as 
alloys, but this may as well have been the copying of 
late German practice as motivated by conservation 
requirements. 

Rarely was metallurgical initiative shown, though 
the use of the strong aluminum-magnesium-zinc al- 
loys in fighter planes was an innovation adopted on 
their own initiative. 

Japanese products were often made with a vast 
deal of handwork and by roundabout methods, not 
because they did not know better methods, since 
some parts are made in up-to-date fashion, but evi- 
dently for lack of processing equipment for rapid, 
large-scale production. Despite this, the workman- 
ship, though seldom up to the German standard, is 
fair and generally adequate for the purpose in hand. 


CONFIDENTIAL 


116 


EXAMINATION OF ENEMY MATERIEL 


Some very poor ball bearings of Japanese make were 
found, made of the conventional steels but sloppily 
heat treated, probably because of poor equipment 
and inadequate inspection. 

On the whole, however, the Japanese implements 
of warfare were of good, usable quality. The Japanese 
bottleneck was more probably in iron for tonnage 
steel rather than in alloying elements. The tonnage 
steel, and even most of the alloy steels, carry residual 
elements, indicating wide use of scrap metal that 
would ordinarily be considered inferior, and un- 
doubtedly much of the second grade scrap that was 
sold to Japan during the appeasement period en- 
tered into implements of warfare for use against us. 

Neither the Germans nor the Japanese went far 
toward conservation of steel alloying elements by 
considered use of the content of such elements found 
in scrap as we did in the National Emergency steels. 

The German scrap situation did not lend itself to 
such a solution as well as does American scrap. Japa- 
nese scrap could have been somewhat more readily 
adapted. In only one case, that of a torsion bar for 
a Panzer tank, was boron used to enhance harden- 
ability, and that was late in the war. 

This project, which covered the examination of 
794 individual samples or shipments of diverse na- 


ture, has been reported in 215 topical reports,^^® 
not many of which are interconnected. A list of the 
titles of these reports as well as a subject index of 
the items examined are given in the final report'*'^^ 
on the project and should be inspected when details 
are sought. 

A general summary of the earlier examinations, 
correlated with published British reports, was pub- 
lished.55® These examinations related chiefly to guns, 
ammunition, and aircraft, and give a picture of 
German and Japanese war metallurgy very similar 
to that reported from a study of automotive equip- 
ment.^''^^ 

Another project dealing with enemy materials 
rather than materiel was Survey Project SP-6, Ab- 
stract of a Confidential Report on Nickel in Japan. 
This project was carried out by the War Metallurgy 
Committee as a result of a request directed to NDRC 
by the Far Eastern Branch, Military Intelligence 
Division G-2, War Department General Staff in 
April 1942. Under this project a voluminous docu- 
ment was abstracted.^^^ Although the document 
contained no useful information on new alloys or 
substitutes for nickel steels, it did yield information 
as to possible bombing objectives to bottleneck Japa- 
nese production of nickel. 


CONFIDENTIAL 


Chapter 9 

MISCELLANEOUS MATERIALS FOR WAR 


91 INTRODUCTION 

U NDER the classification of miscellaneous materials 
for war are grouped a number of investigations 
relating to studies of materials used in miscellaneous 
instrumentalities of warfare that were not integral 
parts of the programs described in the foregoing 
chapters. Although some of these investigations are 
mentioned in other sections of this summary in in- 
stances where phases of the work had direct bearing 
on the program of that section, the references there 
cited covered only the phases of the program being 
discussed. 

9 2 MATERIALS FOR QUARTERMASTER’S 
SUPPLIES 

Several problems were presented by the Office of 
the Quartermaster General for study by NDRC. 
These comprised the development of fused inorganic 
coatings for cooking utensils, investigations of plated 
steel flatware for military use, general metallurgical 
studies of quartermaster’s supplies including meth- 
ods of camouflaging mess gear, and the evaluation of 
the corrosion-resisting properties of an alloy that 
had been suggested for use in quartermaster’s items. 

9.2.1 Fused Coatings for Cooking Utensils 
and Other Quartermaster’s Supplies 

Project NRC-46 (QMC-18), Development of a Suit- 
able and Noncritical Fused Inorganic Coating for 
Cooking Utensils and Other Quartermaster’s Items, 
was established in the laboratories of the Ferro 
Enamel Corporation. The program originally formu- 
lated comprised investigations which might lead to 
the development of fused inorganic coatings for steel 
canteens and cooking utensils, studies of the possible 
use of combinations of fused inorganic coatings and 
metallic coatings for the edges and corners of the 
articles, and the gathering of data from which recom- 
mendations could be drawn for establishing satisfac- 
tory specifications. The Quartermaster Corps desired, 
as quickly as possible, coatings that would be capable 


of withstanding rough usage and would be nonre- 
flective, nontoxic, and adaptable to camouflage. 

Before the project was completed, the metal supply 
situation changed and stainless steel and later alumi- 
num became available for canteens. As a result, the 
aim of the project was changed and the work was 
concentrated on the development of coatings for 
such quartermaster’s articles as spark arresters, tent 
hardware, stoves, stovepipes, and cooking utensils. 
Not only were a number of coatings developed, 
but also trials were made of commercially available 
coatings.^^® 

Two developments made under the project are 
noteworthy, and it is understood that, in part at 
least, they have been adopted by the Office of the 
Quartermaster General. One is a cemented inorganic 
coating applied at low temperatures (under 500 F). 
The other comprises applying a so-called slag coating 
and then over it a thin matte finish of vitreous 
enamel. This coating combines corrosion and erosion 
resistance, and, as it has a matte finish, glare is absent. 
In addition, objects can be finished in olive drab or 
camouflage colors. Samples of the more promising 
coatings were supplied to the Army and Navy liaison 
representatives for the project as well as to the Con- 
servation Division, War Production Board. The 
Military Planning Division of the Office of the Quar- 
termaster General sent a set of these samples to the 
National Bureau of Standards for evaluation. Infor- 
mation as to the results of these tests and the extent 
of the adoption of the coatings developed is not 
available. 


9.2.2 Flatware for Army Use 

In 1941, the necessity for diverting copper, nickel, 
zinc, and chromium to the most essential military 
uses led to the substitution of plain carbon steel for 
nickel-silver and stainless steel in flatware procure- 
ment by the Armed Services. The specifications issued 
at that time, RR-T-56, provided for plating or coat- 
ing steel with tin, nickel, chromium, or silver accord- 
ing to accepted commercial practice, with the usual 
undercoatings of different metals. Subsequently, an 


CONFIDENTIAL 


117 


118 


MISCELLANEOUS MATERIALS FOR WAR 


emergency specification, E-RR-T-56, was issued 
limiting approved coatings to silver directly on steel. 
It soon became clear that flatware made by plating 
silver on steel was not of the anticipated quality. 
Although early difficulties from peeling and blister- 
ing of the coatings were overcome, the susceptibility 
of the ware to staining by rust was seriously objec- 
tionable. In 1942, the Conservation Branch, Produc- 
tion Division, Headquarters, Services of Supply, War 
Department, requested the War Metallurgy Com- 
mittee to make a study of plating silver directly on 
steel. A committee was appointed and Survey Project 
SP-11, Silver Plating of Steel Flatware, was estab- 
lished. The committee consulted with flatware manu- 
facturers as well as with representatives from the 
Armed Services and the War Production Board. A 
comprehensive report on the situation was issued^^® 
and, as there was no known method for fabricating 
silver-plated steel flatware that would not eventually 
rust in service comparable to that required by the 
Armed Forces, a research program was recommended. 
As the result of this report, the Office of the Quarter- 
master General requested that NDRC undertake 
investigations under the control number QMC-21. 
Project NRC-48, Flatware for Army Use, was estab- 
lished at the Reed and Barton Corporation for the 
purpose of having flatware made by various pro- 
cedures for service testing. The contract for the 
manufacture of this flatware was virtually a procure- 
ment contract and the committee for Survey Project 
SP-11 provided the procedures, drew up a test pro- 
gram, and evaluated the results. This committee 
included liaison with the Army and Navy, the War 
Production Board, and the National Bureau of 
Standards, thus knitting together the several investi- 
gations being carried out on the subject. The objec- 
tive of this project was to investigate the use of the 
less strategic metals, for example, silver alloys, other 
metals and alloys, and composite coatings for the 
protection of steel flatware from rusting in service, 
and to coordinate tests and data from the several 
government agencies interested in the subject. 

Lots of approximately 500 pieces of each of thirty- 
five types of mild steel forks plated with electro- 
deposited coatings of silver, chromium, and com- 
posite coatings of these metals with copper and nickel 
were prepared under the supervision of a member of 
the committee. Samples of each type were examined 
by the National Bureau of Standards and a number 
of pieces from each lot were subjected to test in the 


mess halls of Camp Lee, Virginia. These tests were 
conducted by the Quartermaster Board and were 
examined weekly by observers. The unserviceable 
forks were withdrawn from the test and returned to 
the chairman of the committee. 

Part I of the final report^®^ on Survey Project 
SP-11 (QMC-21) gives the results of one full year of 
field service tests. Part II®^^ covers the results of the 
service tests beyond 368 days to a total of 599 days. 
Appended to this report are reports from the Na- 
tional Bureau of Standards, and the Quartermaster 
Board on the parts they played in this cooperative 
effort. A report of the U. S. Naval Engineering Ex- 
periment Station also is appended to bring together 
all the significant reports on the testing of flatware 
for military use. 

As a result of this investigation, the committee 
made recommendations as a guide in the preparation 
of specifications and in the supervision of the manu- 
facture of plated steel flatware for military mess hall 
use. 

^•2-3 General Metallurgical Studies 

In February 1943, the Research and Development 
Branch, Military Planning Division, Office of the 
Quartermaster General, requested the War Metal- 
lurgy Committee to initiate a project to deal with 
miscellaneous metallurgical problems relating to 
quartermaster’s supplies. As a result of this request. 
Project NRC-54, Metallurgical Studies and Surveys 
of Army Quartermaster Corps Supplies, was estab- 
lished at the Massachusetts Institute of Technology. 
Work on this project did not involve extended re- 
search programs but consisted of the study of many 
isolated problems, some of which required incidental 
experimental work for their solution. These prob- 
lems changed constantly because of the changing 
needs of the Armed Forces and also because of the 
constantly changing availability of certain metals 
which had been found satisfactory but for which sub- 
stitution had to be made in the emergency. The 
investigator worked closely with the Office of the 
Quartermaster General and in particular with the 
Boston Quartermaster Depot. 

The final report on the projecU^^ topical and 
fragmentary as in most instances the urgency of the 
need made it impossible to follow through to a 
wholly satisfactory conclusion. Generally speaking. 


PROPERTIES OF MISCELLANEOUS MATERIALS 


19 


the problems were concerned with metals used in 
any form of quartermaster’s supplies from shoe eye- 
lets to gasoline containers. Experimental work and 
consultations covered mountain and ice equipment 
such as ski binders; rock pitons, and ice pitons; cook- 
ing and messing equipment; and miscellaneous items 
such as small tools, shoe eyelets and hooks, toe and 
heel plates, pails, and refuse cans. 

^24 Camouflage of Mess Gear 

Another phase of the foregoing investigation was 
the study of the camouflage of mess gear (QMC-25). 
In the Southwest Pacific Theater, there was a need 
for a surface which would be nonreflecting and at 
the same time would withstand severe shock and ex- 
posure to high temperatures, even to flame tempera- 
tures. A series of experiments led to the preparation 
of a number of canteens coated by a metal spray proc- 
ess. These canteens had a dull surface and various 
colors could be produced by variations in the metal 
powder compositions.^®- As far as could be deter- 
mined by rough tests, these coatings were satisfactory. 
Their resistance to impact, abrasion, and heat, as 
well as their toxicity, was determined by the Na- 
tional Bureau of Standards. Information as to the 
results of these tests and the extent of the adoption 
of the process, if adopted at all, is not available. 

9.2.5 Evaluation of the Corrosion Resistance 
of a Special Alloy Steel 

At the request of the Office of the Quartermaster 
General, Project NRC-91 (QMC-39), Development 
and Evaluation of an Economical Corrosion Re- 
sisting Alloy for Quartermaster Items, was estab- 
lished at Battelle Memorial Institute. The objective 
of this project was to evaluate the corrosion resistance 
of Alcuphos, a special alloy steel developed at the 
Jeffersonville Depot, to determine its suitability for 
possible use in flatware. It was believed that this 
alloy had corrosion-resisting properties which would 
be of value in tropical areas. The corrosion tests per- 
formed on Alcuphos with mild steel, stainless steel, 
and an aluminum alloy for comparison, comprised 
tropical humidity tests, salt-spray tests, industrial at- 
mosphere tests, and spot tests with selected foods. 
These tests demonstrated, in every case, the suscepti- 
bility of Alcuphos to corrosive attack. In some cases. 


the test suggested that Alcuphos is less resistant than 
mild steel. Both stainless steel and the aluminum 
alloy showed excellent resistance to the several corro- 
sive environments.^®® Therefore, the project was 
abandoned. 

93 PROPERTIES OF MISCELLANEOUS 
MATERIALS 

Low -Temperature Properties 
of Metals 

In August 1940, the Office of the Quartermaster 
General requested NDRC to study the physical 
changes occurring in metals and other materials 
under extreme cold conditions as these changes pre- 
cluded the simple adaptation of conventional designs 
and materials used in standard production motor 
vehicles. This information was desired in the devel- 
opment of motorized transport equipment for Army 
use in arctic climates. Action on establishing a project 
was delayed until the problem could be discussed 
with Watertown Arsenal. As a result of this confer- 
ence, the Metallurgy Section of the former Division B 
of NDRC recommended that a thorough study of all 
available data be made before the formulation of a 
definite research program. In March 1941, Project 
B-89, Literature Survey on the Low-Temperature 
Properties of Metals, was established at the Univer- 
sity of Michigan by the former Division B of NDRC. 
The final report on this project comprises seven 
volumes and covers the information available at that 
time on the low-temperature properties of metals 
and alloys, both ferrous and nonferrous. Each major 
group is divided into subgroups, according to alloy 
types.®®4 

The effect of low temperatures on the cleavage frac- 
ture of ship plate is discussed in Chapter 6 of this 
summary report. It is noteworthy also that studies of 
the behavior of ferritic steels at low temperatures 
were the subject of an investigation carried out for 
the Office of Production Research and Development 
of WPB under the supervision of the War Metallurgy 
Committee.® 

Behavior of Metals under Dynamic 
Conditions 

Prior to 1942, the study of the behavior of metals 
under dynamic conditions was concerned princi- 


120 


MISCELLANEOUS MATERIALS FOR WAR 


pally with the assembly of data from notched bar im- 
pact tests. There had been some activity toward 
obtaining information on the performance of metals 
in tension impact. In spite of the abundance of data, 
there was not a clear fundamental understanding of 
the conditions involved in impact loading except in 
the case of elastic behavior. It was well recognized 
that elastic strains were propagated in bars with the 
velocity of sound, but when plastic strain was in- 
volved the behavior of the bar could not be inter- 
preted. If materials were to be subjected to impact 
loading and tested in that manner to destruction, it 
was necessary to be able to interpret the results in a 
manner that would have significance in practical 
applications. 

For some time engineers have believed that many 
machine parts and structures are subject to impact 
loading, and, furthermore, they have observed that 
the performance of some materials when subjected 
to dynamic loading is different from that experi- 
enced under static conditions. To explain these dif- 
ferences, a fundamental concept must be established. 
By the development of this fundamental concept, it 
was hoped that a basic understanding of the dynamic 
performance of metals not only under impact, but 
also under high strain rate and rapid loading condi- 
tions, could be obtained. 

In March 1942, the former Division A of NDRC 
established a project at California Institute of Tech- 
nology to undertake experimental and theoretical 
investigations, for various high rates of strain, of the 
propagation of plastic deformation in wires, bars, 
and beams under conditions in which end effects 
could be neglected. It was believed that the theory 
proposed by von Karman and partially confirmed 
in earlier work under Division A,®®® would be useful 
in connection with the understanding of the mecha- 
nism of projectile impact and penetration. Work on 
this problem was informally requested of Division A 
by the Naval Proving Ground and endorsed by the 
NDRC ad hoc Armor Committee.’^® It was requested 
also by the Bureau of Ordnance, Navy Department, 
under their control number of NO-1 1. Subsequently, 
the Bureau of Ships, Navy Department, requested, 
under their control number NS- 109, work relating 
to the behavior of ship building materials at high 
rates of loading to provide basic data for use in the 
design of structures subjected to shock loading. The 
project was of interest also to the Corps of Engineers 
under their control numbers CE-5 and CE-6. 


With the reorganization of NDRC, the supervi- 
sion of the project was transferred from the former 
Division A to Division 2. In January 1944 the project 
was transferred from Division 2 to Division 18 and 
continued as Project NRC-82 (NS-109), Behavior of 
Metals under Dynamic Conditions. At that time, the 
program was revised to emphasize topics which held 
promise of being of most immediate value to the war 
effort. These comprised studies of impact loading on 
aircraft materials, gun steels, and ship plate. 

According to the von Karman theory of the 
propagation of plastic deformation in solids, the 
velocity of propagation of a plastic strain is less than 
that of an elastic strain; the velocity of propagation 
of this plastic strain decreases with increasing strain 
when the slope of the stress-strain diagrams decreases 
continuously; and plastic strain will increase with 
increasing velocity. When this theory is applied to 
the case of a long prismatic bar put suddenly into 
motion with a constant velocity, if the impact velocity 
is sufficient to produce a strain corresponding to the 
ultimate strength of the material in the bar, necking 
or rupture will occur at the moving end of the bar 
without causing very large plastic deformation 
further along the bar. The impact at which this oc- 
curs is termed the critical velocity. 

The principles of this theory were verified in a 
preliminary manner by Duwez^®® from impact tests 
with long wires. Later tests with short specimens 
verified the existence of a critical velocity.^®^ The 
computation of the critical velocity is based upon the 
static stress-strain diagram. The agreement between 
the experimental and computed critical velocity is 
not too close in all cases. However, data has been 
presented in these investigations to show that the 
dynamic stress-strain diagram is higher in some mate- 
rials than the static diagram. 

Further theoretical work^®* was carried on to take 
into account the reflection of plastic strain waves at 
the end of a bar of finite length. The effect of release 
of the impact load on the performance of bars has 
been considered. A graphical method of analysis was 
developed which is carried through in a more exten- 
sive manner in a general report.^®^ These methods 
of analysis make it possible to establish the stress- 
time relations in a member subjected to tensile im- 
pact. 

It has been found that the simple theory of plastic 
strain propagation cannot be applied to materials 
for which the stress-strain diagram shows a yield 


CONFIDENTIAL 


PROPERTIES OF MISCELLANEOUS MATERIALS 


121 


point. In the interest of this problem a preliminary 
study was made of the mechanism of the progression 
of plastic yielding.^"^ While the results of this study 
did not provide a means of taking care of yielding in 
the strain propagation theory, it gave some signifi- 
cant information. It appears that in the usual static 
tensile test, yielding progresses in jumps and the 
strain associated with these jumps is the strain cor- 
responding to the end of yield on the static stress- 
strain diagram. Actually the strain at yield, whether 
static or dynamic, is not less than the strain at the 
end of yield when considered over a small increment 
of the gage length. 

It is natural to question the validity of the theory 
of plastic strain propagation for compression load- 
ing. An investigation^^^ was made, and it was found 
that the theory holds whenever the compression 
stress-strain diagram is concave downward. Tests 
were made with steel and lead. With the latter mate- 
rial it was shown that the concept of a critical velocity 
holds for the case of compression.The critical velocity 
for the steel is greater than the impact velocity at- 
tainable with equipment at hand. 

Although the experimental work has shown cer- 
tain discrepancies with respect to theory, it is to be 
remembered that the theory is based upon ideal con- 
ditions involving perfect impact by a rigid body. 
Also, the theoretical computations are based upon 
the static stress-strain diagram. The experimental 
work has given definite evidence to the effect that the 
stress-strain diagram under dynamic conditions is 
higher than under static conditions. 

Influence of Impact Velocity on Tensile 
Properties 

While the tensile impact tests on long wires were 
directed toward verification of the theory of the 
propagation of plastic strain, tests were made on 
specimens with a gage length of 8 in. These speci- 
mens were carried to failure and the force-time rela- 
tions were determined. This provided data on the 
influence of impact velocity on the ultimate strength, 
percentage of elongation, percentage of reduction of 
area, and energy required to rupture. More exten- 
sive tests on long wires were made followed by tests 
on 8-in. specimens in the first part of these investiga- 
tions. 567 While the tests on the short specimens pro- 
vided information on specific metals, they also proved 
the existence of a critical velocity. 

Some tests5^2 ^ere directed toward a comparison 


between the experimental and theoretical strain dis- 
tribution curves. The method of computing the re- 
flection and stopping of plastic waves was shown to 
be substantially correct. 

One may well be concerned with the effect of the 
dimensions on the results of impact tests. Such an 
investigation was made.5"3.574 jj^ series of ex- 
periments an investigation was made of the behavior 
of long specimens of a material which exhibits yield- 
ing where it was shown that the velocity of propaga- 
tion is a multivalued function and the strain dis- 
tribution differs from that computed by the theory. 
It was also shown that such a material can sustain a 
stress approximately three times the static yield point 
without the occurrence of plastic strain, provided the 
duration of the application of load is short. Other 
tests were made to determine the influence of gage 
length on the results of tensile impact tests. It was 
found that the critical velocity was not affected by 
the gage length. However, the gage length must be 
less than 4 in. to show the critical velocity clearly. 

Another investigation575 ^as made to study the 
influence of general specimen dimensions and shape 
on the results of the tensile impact tests. From these 
tests it was apparent that if the ratio of length to 
diameter was greater than 13, the results were not 
altered. Furthermore, the shape of the specimen 
within the range considered had no effect on the test 
results. The accuracy of tensile impact test results 
has been studied in some detail.576 xhe experimental 
error in so far as energy measurements are concerned 
is not more than plus or minus 10 per cent. 

Tests were made on a rather large number of fer- 
rous and nonferrous metals and alloys in the de- 
termination of the influence of impact velocity upon 
the tensile properties of these materials. Investiga- 
tions were made over a range of impact velocities up 
to 200 fps. The details of these tests are covered in 
individual reports.577.584 ^ general summary of 
these data is presented in a separate report.585 As a 
result of these investigations taken with the theoreti- 
cal analysis, it was shown that only the force-time or 
stress-time diagrams can be obtained in tensile im- 
pact tests and that these diagrams cannot be trans- 
formed into stress-strain diagrams. The conclusion 
is that in tensile impact tests the results cannot be 
logically referred to values of strain rate. Inability 
to transform these diagrams is due to propagation 
effects which give rise to a nonuniform strain rate 
over the gage length of the specimen. 


CONFIDENTIAL 


122 


MISCELLANEOUS MATERIALS FOR WAR 


Tests made so far indicate that the dynamic tensile 
properties of materials cannot be predicted from 
their static properties, although the order of magni- 
tude of the critical velocity may be predicted with 
reasonable reliability on the basis of the static stress- 
strain diagram. It has been found that the ultimate 
strength of all materials tested so far is never less than 
the static value at impact velocities in the range of 
25 to 200 fps. In plotting the percentage of elonga- 
tion against impact velocity, the data appear to fol- 
low one of three types of relations: 

1. Elongation is constant (either higher or lower 
than the static values) within a certain velocity range 
followed by a decrease in elongation at higher 
velocities. 

2. The elongation increases uniformly to a maxi- 
mum and then decreases with continued increase in 
impact velocity. 

3. The elongation values are scattered with a tend- 
ency to increase with increasing impact velocity and 
then to decrease slightly above a critical impact 
velocity. 

The influence of impact velocity on the energy 
required to rupture the specimen follows the same 
general tendency as the percentage of elongation for 
the materials tested in these investigations. It was 
concluded that, in general, the higher the static 
ultimate strength and percentage of elongation, the 
lower is the percentage of increase of strength and 
elongation under dynamic conditions. 

Some of the work included a study of the influence 
of heat treatment on the tensile impact properties of 
several steels.^'^®’^®^-^^^”'’*® In some it was found 
that, in a steel heat treated to hardnesses of the order 
of 50 Rockwell C, better dynamic properties were ob- 
tained by austempering than by quenching and tem- 
pering. On the other hand, when these same steels 
were heat treated to a hardness of about 30 Rockwell 
C, quenching and tempering appeared to give better 
dynamic properties. To carry this line of investiga- 
tion further, other tests^®® were made specifically on 
an SAE 4340 steel which was heat treated by three 
procedures, namely, quenching and tempering, mar- 
tempering, and austempering. The range of hardness 
covered was from approximately 28 to 49 Rockwell 
C. All these tests were made at an impact velocity of 
about 100 fps. For hardnesses in the range of about 48 
Rockwell C, it was observed that an austemper or a 
martemper treatment gives a slightly higher value of 
energy required to rupture than a quench and temper 


treatment. For hardnesses in the lower range, a 
quench and temper or a martemper treatment gives 
slightly better energy values than an austemper treat- 
ment. These results might be helpful in certain 
applications in the selection of the proper heat treat- 
ment and hardness range for certain specific require- 
ments where it is recognized that impact conditions 
prevail. However, it must be remembered that the 
austempered specimens tested were of very small 
sections and that austempering is not in general ap- 
plicable to large sections. 

Compression Impact 

In the discussion of the development of the theo- 
retical aspects of plastic strain propagation, it was 
stated that the relations established by von Karman 
are believed to hold in the case of compression im- 
pact for materials in which the static stress-strain 
diagram was concave downward. 

A series of tests was made on annealed copper, cold- 
drawn copper, annealed SAE 1020 steel, cold-drawn 
SAE 1020 steel, a zinc base alloy die-casting, and 
lead. It has been shown^^^ that the theory of strain 
propagation is valid in compression for strains which 
are less than those corresponding to the inflection in 
the static compression stress-strain curve. Reasonably 
good evidence had been presented to show the com- 
pressive elastic limit of annealed SAE 1020 steel 
under dynamic conditions to be about 40 per cent 
greater than the static value. The experiments with 
lead have given evidence of the existence of a critical 
velocity of about 100 fps in compression. At impact 
velocities greater than this value, plastic strains 
greater than approximately 35 per cent could not be 
detected in the specimens tested. It appears that the 
velocity of plastic deformation in lead for strains 
greater than 35 per cent is too low to permit longi- 
tudinal displacement of material and, therefore, the 
material is displaced laterally. In view of these results 
the critical velocity of annealed copper, cold-drawn 
copper, cold-drawn SAE 1020 steel, and class B 
armor plate were computed to be 1,050, 1,220, 1,440, 
and 1,750 fps respectively. It is to be noted that these 
critical velocities are considerably above those which 
are found in the case of tension. The principal of 
strain propagation in compression was also con- 
sidered for a practical problem. 

The results of the compression impact studies led 
to a consideration of the mechanism of penetration 
of plates by projectiles from the standpoint of strain 


CONFIDENTIAL 


PROPERTIES OF MISCELLANEOUS MATERIALS 


123 


propagation.^^? Some tests have been made in which 
a projectile 0.224 in. in diameter was fired at copper 
disks of different thicknesses at a velocity of about 
3,900 fps. In plotting the square of the residual veloc- 
ity against the thicknesses of the disks, a definite dis- 
continuity was observed. It is believed that this dis- 
continuity is related to the change of velocity of the 
projectile during penetration. This discontinuity in 
the curve has been interpreted on the basis of the 
theory of strain propagation. These tests were of ex- 
ploratory character and were not carried further. 

Impact on Beams 

In view of the success attained in the application 
of the theory of plastic strain propagation to longi- 
tudinal impact, both experimental and theoretical 
investigations were made on the behavior of beams 
under conditions of impact loading. The investiga- 
tions included tests on small rectangular freely sup- 
ported beams 10 ft long and a theoretical analysis 
of infinitely long beams.^^s xhe materials included 
cold-rolled and hot-rolled low-carbon steel and an- 
nealed copper. Deflection curves at the end of im- 
pact and after the beams returned to rest were 
obtained. A theory was developed for the plastic de- 
formation of an infinitely long beam subjected to 
a concentrated transverse impact of constant velocity. 
The results show that for a material such as low- 
carbon steel, for which plastic deformation is local- 
ized, the observed deflection curve is closely approxi- 
mated by considering the elastic behavior in the 
theoretical case. Two approximations of the moment- 
curvature curve have been given by which the de- 
flection characteristics may be computed for certain 
cases. 

With the development of the theory of propaga- 
tion of plastic bending and its verification, experi- 
ments were made on beams for which the ratio of 
depth to length and the mode of clamping and load- 
ing was somewhat closer to those which might be ex- 
perienced in practice. The impact load was 
obtained by means of a mass moving with a certain 
velocity. The total kinetic energy of the hammer was 
absorbed by the beam. Consequently, the impact 
velocity after initial impact was not constant, as in 
the test utilized to confirm the theory, but decreased 
progressively to zero. An I beam and a rectangular 
beam of the same section modulus, 40 in. long and 
clamped at the end, were investigated. These beams 
were of extruded sections of 24S-T aluminum alloy. 


In general, the results showed that the center deflec- 
tion of the beam increases approximately linearly 
with the kinetic energy of the hammer. It appears 
that, for a given type of beam and a given amount of 
kinetic energy of the hammer, the damage as meas- 
ured by the center deflection is greater for a heavy 
hammer with a low impact velocity than for a light 
hammer with a high impact velocity. Furthermore, 
it was shown that a beam with a greater cross- 
sectional area evidences less damage than another 
beam of the same section modulus. 

Records were made of the force on the beam at 
the point of impact as a function of time. These 
determinations show that the force reaches a max- 
imum value rapidly and then decreases progressively. 
If two beams having the same section modulus but 
different weight per unit length are subjected to the 
same conditions of the impact, the force acting on 
the hammer will be greater for the heavy hammer. 

Impact on Plates 

Interest in the perforation of plates by projectiles 
led to a consideration of the application of the theory 
of strain propagation to the action of a punch at the 
center of a plate under conditions of impact loading. 
For this purpose a preliminary investigation was 
made.^^^ In this work the impact velocities were less 
than 150 fps. Both hot-rolled and cold-rolled plates 
1 /^ in. thick and 7i/4 in. in diameter were employed. 
Three types of punches were used, namely, flat end, 
conical end with 75-degree included angle, and 
conical end with 45-degree included angle. These 
plates were clamped at the periphery. While these 
tests were of preliminary character, they showed that 
a certain velocity exists above which the maximum 
deflection in the plate decreases markedly. This veloc- 
ity appears to be independent of the shape of the 
punch. Deflection curves are given for various veloc- 
ities up to approximately 150 fps and for static 
loading. 

In view of the results of the preliminary tests with 
plates, a theoretical study was made on the plastic 
bending of circular plates with both static and im- 
pact loading at the centec.^""’^^ A reasonably satisfac- 
tory agreement was obtained between theoretical 
and experimental static deflection curves. In gen- 
eral, it was found that the law of propagation of 
bending strain which had been found to hold for 
beams is also true for plates. 

The small diameter of the plates used in the pre- 


CONFIDENTIAL 


124 


MISCELLANEOUS MATERIALS FOR WAR 


vious work did not permit as extensive conclusions 
as were desired. An investigation was made on steel 
plates 1/4 in. thick, 6 ft and 3 ft in diameter, loaded 
in impact at the center with a spherical punch. ^92 
In these tests the plates were supported at the edge 
and stuck at the center at different impact velocities 
and for several durations of impact.Velocities ranged 
from about 55 to 205 fps, with the duration of im- 
pact between 0.4 and 2 msec. The deflection curves 
were determined at the end of impact and after the 
test was completed. The results indicate that the 
point along the diameter at which the deflection is 
zero travels from the center of the plate toward the 
support proportionally to the square root of the 
time. The relation is in agreement with the theory 
based on bending stress only and is not in agreement 
with the membrane theory also discussed in the re- 
port of this work. It appears from these results that 
a theory covering the dynamic deflection of a plate 
must include both tensile and bending stresses. 

A series of tests was made on a Zamac II die-cast 
alloy for the purpose of investigating its dynamic 
properties for a specific application.^®^ Tensile im- 
pact and static-bend tests were made at temperatures 
between —58 F and 70 F. 

Strain Rate 

In the investigation of longitudinal impact, the 
results were obtained with the aid of force-time 
curves determined during the impact tests. It is im- 
portant to realize that these force-time diagrams can- 
not be transformed into stress-strain diagrams. This 
restriction is based upon an understanding of the 
theory of strain propagation. By applying the theory 
of strain propagation, it is possible to determine the 
rate of strain at any specific point along the specimen 
as a function of time. From these considerations, it 
was shown that the rate of strain varies widely from 
one point to another and that the strain rate at any 
point may differ markedly from the average strain 
rate. Therefore, the results of tensile impact tests 
must be expressed in terms of impact velocity and 
not in terms of strain rate. 

In order to determine the influence of pure strain 
rate on the properties of materials, it is necessary 
to conduct a test in which propagation effects are 
either eliminated or very markedly minimized. To 
this end, special equipment has been devised.^®^ A 
tubular specimen was employed in such a manner 
that a uniform circumferential stress was introduced. 


The stress was obtained by means of fluid pressure 
applied within the tubular specimen in such a man- 
ner that strain rates up to approximately 200 in. per 
in. per sec were attained. These tests were made on 
MS, HTS, and STS ship plate. Since the specimens 
consisted of thin-walled tubes approximately 0.013 
in. thick, inhomogeneities and segregation in the 
structure were found to be highly influential on the 
results of the test. 

The results of the uniaxial strain rate tests have 
shown that for these particular materials the ultimate 
strength and proportional limit increases with in- 
creasing strain rate in the range from approximately 
zero to about 200 in. per in. per sec. Evidence has 
been presented to show that the ultimate strength 
attains an approximately constant value at rates of 
strain as high as about 200 in. per in. per sec. The 
proportional limit becomes equal to the ultimate 
strength at a rate of strain of about 70 in. per in. per 
sec. The values of maximum uniform strain at rup- 
ture were quite scattered; therefore, no relation 
could be found between these measurements and the 
rate of strain. It was of considerable interest to note 
in these tests that the ultimate strength of these three 
materials as determined with the tubular specimens 
at a strain rate of about 200 in. per in. per sec. was 
about the same as that determined in the tensile 
impact tests in the range of impact velocities of 25 to 
200 fps. Some of the specimens of the MS ship plate 
cracked open prematurely in both static and dynamic 
tests. Izod impact tests were made on these same 
materials, and there did not appear to be any correla- 
tion with premature cracking in the tubular type of 
specimens. As a result of these investigations it ap- 
pears that the increase of ultimate strength resulting 
from dynamic effects is about the same whether 
determined under conditions of high pure rate of 
strain or under tensile impact conditions. 

The pure strain rate tests just described were ap- 
plied to samples taken from two 76-mm gun tubes 
which showed markedly different behavior when 
ruptured by detonation of a high-explosive shell in 
the bore of the tube.^®^ One of these tubes failed in 
a ductile manner while the other fragmented badly. 
The dynamic tests were made at a strain rate as high 
as 190 in. per in. per sec. Static tensile tests and Izod 
impact tests made on these materials had revealed 
the expected differences in the two gun tubes, one 
of which was slack quenched, quenched in solid, the 
other fully quenched, quenched as a tube. This fact 


CONFIDENTIAL 


PROPERTIES OF MISCELLANEOUS MATERIALS 


125 


was not stated in the progress report.^^^ Tests on the 
uniaxial thin-walled specimens at high strain rates 
showed that the gun tube which failed in a brittle 
manner had a very low uniform maximum strain, 
while the gun tube that failed in a ductile manner 
had a much higher uniform maximum strain. No 
better differentiation was obtained by these tests, 
however, than was obtained by ordinary tensile and 
impact tests. 

Rapid Loading 

The research up to this point was concerned with 
the influence of impact velocity and strain rate on the 
properties of metals and alloys. As a result of these in- 
vestigations, a reasonably clear picture has been 
secured of the conditions prevailing under an impact 
type of loading. This condition involves an almost 
instantaneous setting into motion of some part of a 
structural member. Such a condition gives rise to 
the propagation of strain waves which, under certain 
conditions, may be disastrous to the structure. It was 
shown that with impact loading and with high strain 
rates the proportional limit and ultimate strength 
are greater than with static loading. With this knowl- 
edge one may examine the dynamic loading condi- 
tions which may prevail in the practical case. 

One is confronted with the difficulty of finding 
very many structures in practice that are subject to 
true impact loading. Usually the load may be applied 
rapidly to some specific value, maintained at that 
value for a specified length of time, and released or 
changed to another value. Since it has been shown 
that the proportional limit is higher for high rates of 
strain than for static loading, one may question the 
time for which a rapidly applied load can be sus- 
tained without causing permanent deformation. 

This problem has been considered in a preliminary 
investigation.^^® Very simple equipment was as- 
sembled for this study and, while it was inadequate 
for a precise examination of such phenomena, pre- 
liminary indications were obtained which appear to 
be significant. The results showed that it was possible 
to maintain a stress which had been applied rapidly 
for a short time without causing plastic deformation 
even though that stress was above the static elastic 
limit. 

It was recognized that in order to obtain accurate 
information on this subject, with a shorter time in- 
terval for loading and time of sustained load, special 
equipment was required. Therefore a hydropneu- 


matic machine was designed to fulfill the require- 
ments of this investigation.®®^ The machine was 
designed to attain a tensile load of 20,000 lb in ap- 
proximately 5 msec and to permit that load or any 
fraction of it to be maintained for any desired length 
of time. Provision was made for making the proper 
record of the tests. 

Summary 

The investigations covered in this research were 
concerned primarily with impact in tension, com- 
pression, and bending. The theoretical relations 
concerning the propagation of plastic strain were 
presented and checked experimentally. In addition, 
specific data were obtained on the influence of im- 
pact velocity on the tensile properties of a relatively 
large number of metals and alloys. Investigations 
were made also on the influence of strain rate on the 
properties of a few ferrous alloys. 

The foregoing work led to preliminary tests in the 
study of rapid loading as distinguished from impact 
loading. This approach appears to have the greatest 
practical significance and, if further work were to be 
done in the field of the dynamic properties of metals 
and alloys, this phase should be pursued. Equipment 
was designed by which such studies can be carried on. 

The foregoing discussion was taken from the final 
report on Project NRC-82 (NS-109) prepared by 
California Institute of Technology.®®® As there was 
no promise of the work’s yielding results of practical 
significance in the war effort, the project was ter- 
minated in December 1944. The investigation with 
respect to the effect of explosive impact on armor 
plate, ship plate, and aircraft materials is by no 
means completed, however. It is the belief of mem- 
bers of the staff of Division 18 that the attainable 
velocities were too low and that the simplest way to 
attain explosive velocity is to use explosives. This 
procedure is discussed in Sections 2.2 and 6.1.2 in 
connection with the development of a direct explo- 
sion test for armor and ship plate. 

In April 1945, the Office of the Chief of Engineers 
requested NDRC to undertake further work on the 
dynamic properties of steels used in reinforcing con- 
crete (Control No. CE-36.01). It was proposed that 
“additional data on impact stresses in the plastic 
range ... be developed, particularly the increase in 
elastic limit for load applied in 0.005 sec or less.” 
This work was not undertaken for the same reason 
that the original project was terminated. 


CONFIDENTIAL 


126 


MISCELLANEOUS MATERIALS FOR WAR 


9.3.3 Effects of Impurities on the 

Ferromagnetism of Nonferrous Alloys 

Instrument housings and various parts in the 
neighborhood of aircraft instruments of the magnetic 
type need to have low magnetic susceptibility and 
magnetic moment in order that the instruments may 
give correct indications. Brass and bronze castings, 
wrought brass, and cast and wrought aluminum al- 
loys are commonly used in these locations, since they 
are but slightly magnetic. However, all these alloys 
contain small amounts of iron, and, when they are 
prepared from secondary metals, it is difficult and im- 
practical to keep the iron content exceedingly low or 
to hold it at any exact level. The iron content is the 
principal cause of magnetism. 

At the request of Frankford Arsenal, the Office of 
the Chief of Ordnance requested NDRC to investi- 
gate the effects of impurities on the ferromagnetism 
of nonferrous alloys. Project NRC-79 (OD-156) was 
established at Lehigh University with the aim of 
determining the degree of magnetic interference 
exerted by the common alloys with various iron con- 
tents, and the possibility of controlling this influence 
by variation in composition, heat treatment, aging, 
and plastic deformation. 

Few common nonferrous alloys regularly incorpo- 
rate relatively large amounts of iron as an essential 
alloying element to confer strength, as in manganese 
bronze or manganese aluminum bronze. These are 
covered by Federal Specification QQB-726, composi- 
tions B and C, for castings. These alloys exert too 
much magnetic interference to be applicable to the 
purposes under examination. 

The common copper-base castings are the bronzes, 
containing 3 to 8 per cent of tin, 3 to 10 per cent of 
zinc, and up to 10 per cent of lead, with iron usually 
in the range of 0.05 to 0.25 per cent. Such alloys are 
covered by Federal Specifications QQB-691a, com- 
positions 2 and 11. 

In the as-cast condition, it may be necessary to hold 
the iron content below 0.10 per cent to reach the 
desired degree of freedom from magnetism. In dif- 
ferent castings, or with different rates of cooling of 
the castings, irregularities in behavior may appear, 
since the iron in solid solution is relatively ineffec- 
tive; whereas, if it is thrown out of solution, as by 
slow cooling of the casting, it becomes effective in 
producing magnetism. With very high iron content. 


cold working, as by cold rolling or cold forging, may 
also throw iron out of solution. 

However, by heating the casting to 1475 to 1600 F, 
most or all of the iron is taken into solution and can 
be retained in solution by quenching from such a 
temperature. This treatment induces satisfactory 
nonmagnetic behavior up to an iron content of 
about 0.30 per cent. Annealing the quenched alloys 
at 1200 F throws the iron out of solution and makes 
the tolerance revert to about 0.10 per cent; annealing 
at 1100 F reverts it to about 0.20 per cent. 

The yellow brass casting alloy QQB-621, composi- 
tion B, behaves much as do the bronze castings, but, 
in the solution-quenched condition, can tolerate a 
bit more iron. 

Rolled yellow brass, QQB-611a, composition C, 
with about 2/3 copper, 1/3 zinc, is much more mag- 
netic for a given iron content than are the cast alloys 
studied. Without solution quenching it tolerates 
only about 0.04 per cent iron. Solution-quenched, it 
can tolerate 0.15 per cent. A stress-relieving anneal 
at 575 F of hard-rolled brass materially increases its 
magnetism. True annealing at 930 F increases it, but 
not so much as does the lower temperature. That is, 
at 930 F some of the iron is being taken into solution. 

The plastic deformation produced by rolling or 
forging makes the iron come out of solution very 
much more readily than it does in a casting of com- 
parable composition. 

It is possible that this sensitiveness to iron may be 
connected with the presence of the beta copper-zinc 
phase in the alloy tested. 

A few commercial aluminum alloys also have been 
studied. Commercial aluminum carries much higher 
iron content than the copper-base alloys do. How- 
ever, a few compositions used for commercial sand 
and permanent mold castings and a couple of forg- 
ing compositions were examined and found to show 
so little magnetism as to give no concern about their 
use. In such alloys the iron is probably combined 
with aluminum into compounds that are practically 
nonmagnetic. In one of the sand casting alloys tested, 
1 per cent of iron was present without harmful 
results. The details of the methods used and the 
results of this investigation are given in four prog- 
ress reports'^^^ ®^- and summarized in a final report.®®^ 

This project was transferred from NDRC to the 
Office of the Chief of Ordnance in May 1945 and is 
being continued by that office under a direct contract. 


CONFIDENTIAL 


CONSERVATION, SUBSTITUTION, AND PROCESSING 


127 


94 CONSERVATION, SUBSTITUTION, 

AND PROCESSING OF MISCELLANEOUS 
MATERIALS 

Although most problems involving the conserva- 
tion, substitution, or processing of various materials 
were studied by the War Metallurgy Committee at 
the request of the War Production Board, several 
survey projects in this field were conducted at the 
direct request of the Armed Services and advisory 
reports were issued for NDRC. These covered a 
variety of subjects such as the engineering applica- 
tions of chromium plating, rivets and rivet steels, 
rare metal contacts, and the reclaiming of lead- 
bearing copper alloy scrap. The requests for these 
studies also asked for recommendations on the re- 
search necessary. In most of these cases, the survey 
projects were able to secure from industry sufficient 
information on the problems to obviate the necessity 
of establishing research projects. 

Research projects were established on two con- 
servation problems; the heat treatment of National 
Emergency [NE] steels and the hardenability of cast 
alloy steels. Although these projects were mentioned 
in connection with armor in Chapter 2 of this report, 
their objectives and results were not described. 

Applications of Chromium Plating 

In order to provide a basis for the establishment of 
research investigations on the use of chromium 
plating in war materiel, in March 1942 the Office 
of the Coordinator of Research and Development 
and the Bureau of Aeronautics, Navy Department, 
requested the War Metallurgy Committee to study 
the industrial applications of chromium plating. 
Under Survey Project SP-2, Industrial Application 
of Chromium Plating, a correlated abstract of ap- 
proximately 300 articles and patents selected from 
some 10,000 was prepared. This review^^^ does not 
cover new experimental work but is a useful sum- 
mary of published and unpublished information 
dealing with the industrial nondecorative uses of 
chromium plating. It describes many successful ap- 
plications for parts subject to severe wear, that is, 
gages, tools, dies, etc. While uses in war materiel are 
not described in detail, reference is made briefly to 
the use of chromium plating for the reduction of 


erosion in guns and for decreasing the wear of air- 
craft engines and propellors. To familiarize designers 
and engineers with the possibilities and limitations 
of the use of chromium plating, a revised edition of 
the report was distributed widely throughout in- 
dustry by the War Metallurgy Committee. 

Although no projects were established by Division 
18 or the War Metallurgy Committee on this subject 
as a result of the survey, investigations of the use of 
chromium plating in guns were conducted by Water- 
town Arsenal and Division 1, NDRC. 


9.4.2 Proposed Research on Rivets and 
Rivet Steels 

At the request of the Coordinator of Research and 
Development, Navy Department, the War Metal- 
lurgy Committee established Survey Project SP-8 in 
August 1942 to review the Bureau of Ships Research 
Memorandum No 3-41, Rivet Rod and Rivets: The 
Relation of Chemical Composition to Their Phys- 
ical and Metallurgical Properties, and Report No 
3179-17A of the Materials Laboratory, Navy Yard, 
New York, and to appraise the proposed research 
project. 

It was the consensus of the revie wers^^s that the 
development of a superior rivet steel was essentially 
a metallurgical problem which could be solved using 
the alloy elements available at that time. The use of 
the alloy steels proposed by the Navy Department 
was no longer feasible because the alloying elements 
needed were no longer readily available. It was be- 
lieved, however, that the Navy Department was in 
the best position to decide whether a research pro- 
gram was advisable. It was estimated that an ade- 
quate program would cost approximately $20,000 
and require six months for its completion. No project 
was established by Division 18 or the War Metallurgy 
Committee. 


9.4.3 Rare Metal Electrical Contacts 

In May 1942 the Conservation Branch, Resources 
and Production Division, Army Service Forces re- 
quested the War Metallurgy Committee to under- 
take a study of the current osmium situation, which 
had become critical. The yearly consumption of 


CONFIDENTIAL 


128 


MISCELLANEOUS MATERIALS FOR WAR 


osmium was about 2,400 ounces, yearly production 
was about 600 ounces, and stocks were approximately 
1,000 ounces. It was evident that, unless consump- 
tion was curtailed sharply, military needs could not 
be supplied. The development of substitutes for 
osmium was recommended. 

As a result of this request. Survey Project SP-16, 
Rare Metal Electrical Contacts, was carried out. 
Although it was found that the stock of osmium 
available for military and civilian use was about 
6,100 ounces instead of 1,000 ounces, it was evident 
that the supply and demand had to be brought into 
balance to meet military needs. The report on the 
project 606 reviews the osmium situation and makes 
useful suggestions relative to the substitution, con- 
servation, and increased supply. It was believed that 
research in this held would be better carried out by 
industry, and it was recommended that osmium be 
placed under allocation by the War Production 
Board to insure its most effective use. 

Subsequently, the Conservation Branch, Produc- 
tion Division, Headquarters, Army Service Forces, 
requested a second report on this subject under their 
control number SOS-3, Possibility of Interchangeable 
Use of the Materials and Alloys of the Platinum 
Group, Silver, Tungsten, and Others, in Electrical 
Contacts. Survey Project SP-16 was, therefore, re- 
activated for the purpose of making the requested 
study. The report on this phase of the survey®^^ re- 
views the various types of contact materials and the 
problems involved in the functioning of electrical 
contacts. The aim of the discussion of contact mate- 
rials was to offer aid in the selection of a few prom- 
ising materials for test in newly designed equipment 
and in considering possible substitutions. It is 
stressed that the complexity of the contact phenom- 
ena is such that final selections cannot be made from 
existing data and that actual tests of promising mate- 
rials must be made in the specific device under 
operating conditions when possible. Otherwise very 
carefully simulated operating conditions must be im- 
posed to determine if a proposed material is ade- 
quate. 

Upgrading of Lead-Bearing Copper 
Alloy Scrap 

Another survey made at the request of the Con- 
servation Branch, Production Division, Head- 


quarters, Army Service Forces was of methods of 
reclaiming lead-bearing copper alloy scrap for re- 
use. A special committee appointed by the War 
Metallurgy Committee studied this problem and sub- 
mitted a report in March 1943.®^^ 

Three types of scrap were involved in the study: 
(1) screw machine turnings and borings, (2) miscel- 
laneous cast bronze, cast red brass, and yellow brass 
with lead as a major constituent, and (3) high-leaded 
bronze such as railroad car bearings. The committee 
recommended that, in case the scrap was not being 
utilized in an economical manner, additional melt- 
ing capacity be installed to handle the first type of 
scrap, and additional converter and fire-refining ca- 
pacity be installed to handle the second and third 
types. It was stressed that the problem was not the 
lack of a suitable method to handle the scrap. The 
committee concluded that no research was necessary. 

9.4.5 Heat Treatment of National 
Emergency Steels 

The formulation and adoption of the NE steels to 
replace the standard steels and to conserve critical 
alloying elements was one of the outstanding metal- 
lurgical accomplishments of World War II. In order 
to establish proper heat treatments to utilize these 
steels to full advantage in ordnance materiel, more 
information was needed on their cooling rates. This 
investigation was undertaken by the Research Lab- 
oratories Division of General Motors Corporation 
under Project NRC-55, Heat Treatment of National 
Emergency Steels for Use in Tanks, Combat Cars, 
Gun Mounts, and Other Ordnance Materiel. Al- 
though the project was established on the recom- 
mendation of the War Metallurgy Committee, it was 
subsequently endorsed by the Office of the Chief of 
Ordnance and conducted under their control num- 
ber OD-115. 

To determine the cooling rates and cooling times, 
a procedure was worked out and special equipment 
constructed.1^6 In addition, an accurate cooling 
curve temperature recorder was developed with the 
desired sensitivity for recording temperatures simul- 
taneously at four positions in the test specimen.!-^ 
In the preliminary phase of the investigation, the 
effects of composition and the degree of hardenability 
upon cooling rates along the length of the standard 
Jominy hardenability test bar, end-quenched from 


CONFIDENTIAL 


CONSERVATION, SUBSTITUTION, AND PROCESSING 


129 


1500 F and 1650 F, were determined for two NE 
steels, NE 9420 and NE 9445, as well as SAE 1115 and 
SAE 1045425 These data were obtained from cooling 
curve records produced by the same recording equip- 
ment to be used for studies of the quenching of 
rounds and plates and were necesary for an ac- 
curate correlation between cooling rates in the hard- 
enability test bar and those in plates and rounds. In 
the final phase of the investigation, the cooling rates 
and cooling times in different round and plate sec- 
tions quenched in water were studied. Data were 
taken at the center and at three other locations in 
1-in., 2-in., 3-in., and 4-in. rounds of NE 9445 or 
NE 9450 steels, and at the center and at three other 
locations in i/^-in., i/^-in., 1-in., 2-in., and 3-in. plate 
specimens of 0.34 per cent carbon armor plate steel. 
Also studied were quenching experiments for deter- 
mining the effects of (1) the change of quenching 
temperature from 1525 F to 1650 F, (2) the presence 
or absence of scale prior to quenching, (3) the change 
of water temperature from 55 F to 75 F and 80 F, and 
(4) variation of water velocity over a range of from 
0 to 1,000 fpm. The application of this work in the 
study of the metallurgy of armor is discussed briefly 
in Section 2.3.3 of this report. 

These data permitted the correlation of cooling 
rates and cooling times in plate and round sections 
quenched in water with similar data on the standard 
Jominy end-quenched hardenability bars, and the 
preparation of usable charts showing this correlation. 

9.4.6 Hardenability of Cast Alloy Steels 

A project closely related to the studies of the heat 
treatment of NE steels and of equal value in the war 
effort was Project NRC-83A, Hardenability of Cast 
Steels for Use in Ordnance Materiel. The investiga- 
tion was financed by the American Brake Shoe Com- 
pany and was conducted under the general supervi- 
sion of the War Metallurgy Committee. It was estab- 
lished in March 1944 with the objective of (1) deter- 
mining the composition ranges, employing a mini- 
mum of strategic alloying elements, that would be 
satisfactory for the production of steel castings under 
Federal Specification QQ-S-681b, (2) investigating 
the minimum strategic alloy content that would be 
adequate for tank armor, in anticipation of the pos- 
sible need for revision of cast araior specifications to 


effect further conservation of the alloys, and (3) ex- 
amining the relationships between chemical composi- 
tion, mechanical properties, tempering character- 
istics and hardenability for heat-treated cast steels. 

The last of these objectives produced many data 
of wide applicability in the utilization of alloy steels 
to attain high strength and toughness. Of most gen- 
eral value are the hardenability data for the deeper 
hardening cast alloy steels. Thirty-three heat-treated 
cast alloy steels were made and tested. The program 
included the evaluation of mechanical properties at 
several hardness levels for quenched and tempered 
1-in. rounds (tensile tests) and ^-in. squares (Izod 
impact tests) and of hardenability as measured by the 
standard Jominy end-quench tests. The applica- 
tion of the results of this investigation to the metal- 
lurgy of low-alloy homogeneous armor is also dis- 
cussed in Section 2.3.2 of this report. 

Although the investigation was closed as a correla- 
tion project for the NDRC at the end of World 
War II, it is being continued by the American Brake 
Shoe Company. 

Acceptance Tests for Plain Carbon 
Steel Forgings 

It was thought that a program of study on plain 
carbon steel forgings, similar to that carried out for 
gun tubes and discussed in Chapter 3 of this report, 
should yield information of considerable practical 
value to those making plain carbon steel forgings for 
the Armed Services and to those responsible for the 
writing of specifications for plain carbon steel forg- 
ings for ordnance materiel. At the request of the 
Office of the Chief of Ordnance under control num- 
ber OD-114, Project NRC-58, Acceptance Tests for 
Plain Carbon Steel Gun Forgings and Other Ord- 
nance Forgings, was established at Carnegie Institute 
of Technology in April 1943. The program covered 
a statistical analysis of the transverse ductility in 
plain carbon forging steel represented by SAE 1045 
and included studies of the effect of the direction to 
fiber of forging, the effect of eight different heat 
treatments including normalizing, the effect of ho- 
mogenization, the effect of the degree of forging 
upon the reduction in area, and the effect of banding. 

A very complete metallurgical investigation was 
made of one plain carbon steel forging. In addition. 


CONFIDENTIAL 


130 


MISCELLANEOUS MATERIALS FOR WAR 


a thorough statistical study was made o£ tensile large in quenched and tempered plain carbon steel 
test data received from companies making forgings forgings as in alloy gun tube forgings. Attempts to 
for the Armed Services. reduce this variation significantly by high tempera- 

On the average, the maximum variation of trans- ture homogenization treatments all failed.®*^*^ The 
verse reduction of area was found to be about as project was terminated in August 1944. 


CONFIDENTIAL 


BIBLIOGRAPHY 


Numbers such as Div. 18-10-M2 indicate that the document listed has been microfilmed and that its title appears in 
the microfilm index printed in a separate volume. For access to the index volume and to the microfilm, consult the Army 
or Navy agency listed on the reverse of the half-title page. 


1. Bibliography on Armor, A. P. Projectiles, and the Welding of 
Armor, Vol. 3, Watertown Arsenal, April 1945. 

2. Indexing of Division 18 NDRC Reports: Section I — Subject 

Index of Projects; Section II — List of Research and Survey 
Projects; Section III — List of Reports, Helen L. Purdum, 
OSRD 6604, Advisory Report M-660, National Academy 
of Sciences, February 1946. Div. 18-10-M2 

3. Indexing of JtPr Metallurgy Committee Reports to the War 

Production Board, Advisory Report Special-8, Oct. 24, 
1945. Div. 18-10-Ml 

4. The Effect of Impurities in Aluminum Alloys, Zay Jeflfries, 

OSRD 1731, Advisory Report M-124, National Academy 
of Sciences, Aug. 18, 1943. Div. 18-101. 3-Ml 

5. Fatigue and Impact Characteristics and Notch Effect in Tension 

of Artificially- Aged Aluminum Alloys, OSRD 3579, Progress 
Report M-216, National Academy of Sciences, Apr. 18, 
1944. Div. 18-101. 3-M3 

6. High Temperature Properties of Light Alloys. Part I — Alumi- 
num, L. L. Wyman, OSRD 3607, Final Report M-251, 
National Academy of Sciences, Apr. 15, 1944. 

Div. 18-101. 3-M2 

7. High Temperature Properties of Light Alloys. Part II — Alag- 
nesium, L. L. Wyman, OSRD 4150, Final Report M-292, 
National Academy of Sciences, Sept. 18, 1944. 

Div. 18-102.1-M4 

8. Correlation of Information Available on Fabrication of Aluminum 

Alloys. Section I — Classification and Analysis of the Forming of 
Various Parts, Vol. I, George Sachs, D. T. Doll, and others, 
OSRD 1673, Final Report M-71, Case School of Applied 
Science, July 23, 1943. Div. 18-101. 1-Ml 

9. Correlation of Information Available on the Fabrication of Alumi- 
num Alloys. Section I — Classification and Analysis of the Forming 
of Various Parts, Vol. II, George Sachs, George B. Espey, 
and others, OSRD 3060, Final Report M-132, Case School 
of Applied Science, Dec. 15, 1943. Div. 18-101. 1-M3 

10. Correlation of Information Available on the Fabrication of Alumi- 

num Alloys. Section II — Examples of Fabricating Individual 
Parts, Vol. I, George Sachs, D. T. Doll, and others, OSRD 
1674, Final Report M-80, Case School of Applied Science, 
July 23, 1943. Div. 18-101. 1-M2 

11. Correlation of Information Available on the Fabrication of Alumi- 

num Alloys. Section II — Examples of Fabricating Individual 
Parts, Vol. II, George Sachs, D. T. Doll, and others, OSRD 
3061, Final Report M-155, Case School of Applied Science, 
Dec. 15, 1943. Div. 18-101. 1-M4 

12. Correlation of Information Available on the Fabrication of Alumi- 
num Alloys. Section III — Summary, Contents, and Index of 
Sections I and II, George Sachs, OSRD 3063, Final Report 
M-156, Case School of Applied Science, Dec. 15, 1943. 

Div. 18-101. 1-M5 

13. Correlation of Inf ormation Available on the Fabrication of Alumi- 
num Alloys. Section IV — Survey of the Properties of New 
Aluminum Alloys, Parts I, ll, and III, George Sachs, George B. 
Espey, and others, OSRD 3296, Final Report M-171, Case 
School of Applied Science, Feb. 1, 1944. Div. 18-101. 11-Ml 

1 4. Correlation of Information Available on the Fabrication of Alumi- 

num Alloys. Section IV — Survey of the Properties of New 
Aluminum Alloys, Part IV, George Sachs, OSRD 3554, 
Final Report M-186, Case School of Applied Science, 
Apr. 10, 1944. Div. 18-101. 11-M2 


15. Correlation of Inf ormation Available on the Fabrication of Alumi- 
num Alloys. Section IV — Survey of the Properties of New Alu- 
minum Alloys, Part V, George Sachs, George Espey, and 
others, OSRD 4188, Final Report M-348, Case School of 
Applied Science, Sept. 15, 1944. Div. 18-101.1 1-M3 

16. Correlation of Information Available on the Fabrication of Alumi- 
num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part I — General Introduction; Part II — 
Effects of Non-Uniform Stresses and Strains, George Sachs and 
J. D. Lubahn, OSRD 4348, Final Report M-382, Case 
School of Applied Science, Nov. 2, 1944, pp. 17-18. 

Div. 18-101. 12-Ml 

16a. Ibid., pp. 1-28. 

16b. Ibid., pp. 29-51. 

17. The Correlation of Information Available on the Fabrication of 
Aluminum Alloys. Section V — Formability of Aluminum Alloys 
for Use in Military Aircraft: Part III — Stretch Forming of 
Angles with Outer Leg in Tension, George Sachs and J. D. 
Lubahn, OSRD 4626, Final Report M-447, Case School 
of Applied Science, Jan. 17, 1945. Div. 18-101. 12-M2 

18. Correlation of Inf ormation Available on the Fabrication of Alumi- 

num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part IV — Fundamentals of Pure Bending 
of an Ideal Plastic Metal Under Conditions of Plane Stress, 
George Sachs, J. D. Lubahn, and J. M. Taub, OSRD 
4940, Final Report M-478, Case School of Applied 
Science, Apr. 26, 1945. Div. 1 8-101. 12-M3 

19. Correlation of Information Available on the Fabrication of Alumi- 
num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part V — Simple Bending of Rectangular 
Shapes by Means of Dies, George Sachs, J. D. Lubahn, and 
J. M. Taub, OSRD 5014, Final Report M-487, Case 
School of Applied Science, Apr. 26, 1945. 

Div. 18-101. 12-M4 

20. Correlation of Information Available on the Fabrication of Alumi- 

num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part VI — Stretching of Rectangular Bars, 
George Sachs, J. D. Lubahn, and W. F. Brown, Jr., OSRD 
5332, Final Report M-536, Case School of Applied Science, 
July 13, 1945. Div. 18-101. 12-M5 

21. Correlation of Inf ormation Available on the Fabrication of Alumi- 
num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part VII — Experimental Strain Analysis 
of Bent Rectangular Shapes, George Sachs, J. D. Lubahn, 
and J. E. Schmitt, OSRD 6205, Final Report M-616, Case 
School of Applied Science, Oct. 23, 1945. 

Div. 18-101. 12-M6 

22. Correlation of Information Available on the Fabrication of Alumi- 
num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part VIII — Combined Bending and Ten- 
sion of Rectangular Bars, George Sachs, J. D. Lubahn, and 
J. E. Schmitt, OSRD 6331, Final Report M-588, Case 
School of Applied Science, Nov. 19, 1945. 

Div. 18-101. 12-M7 

23. Correlation of Information Available on the Fabrication of Alumi- 

num Alloys. Section V — Formability of Aluminum Alloys for Use 
in Military Aircraft: Part IX — Bending of T-Sections, George 
Sachs, J. D. Lubahn, and L. J. Ebert, OSRD 6332, Final 
Report M-591, Case School of Applied Science, Nov. 19, 
1945. Div. 18-101. 12-M8 


CONFIDENTIAL 


131 


132 


BIBLIOGRAPHY 


24. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads, 
Part I, Maxwell Gensamer, W. T, Lankford, Jr., and J. T. 
Ransom, OSRD 1940, Progress Report M-141, Carnegie 
Institute of Technology, Oct. 15, 1943. 

Div. 18-101. 2-Ml 

25. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads. 

Part I — Development of Tests for Forming Limits; Stress-Strain 
Curves Under Combined Loads, Maxwell Gensamer, W. T. 
Lankford, Jr., J. T. Ransom, and John Vajda, OSRD 5282, 
Final Report M-527, Carnegie Institute of Technology, 
June 19, 1945. Div. 18-101. 2-M3 

26. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads, 
Part II, J. R. Low, Jr., and T. A. Prater, OSRD 4052, 
Final Report M-320, Pennsylvania State College, Aug. 22, 

1944. Div. 18-101. 2-M2 

27. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads. 

Part II — Forming Limits for Aircraft Sheets at Room Temper- 
ature, Maxwell Gensamer, W. T. Lankford, Jr., and others, 
OSRD 5283, Final Report M-528, Carnegie Institute of 
Technology, June 29, 1945. Div. 18-101. 2-M4 

28. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads. 

Part III — Effect of Aging at Room Temperature on the Properties 
of 75S in the Circular Hydraulic Bulge Test, Maxwell Gensamer, 
W. T. Lankford, Jr., and John Vajda, OSRD 4832, Final 
Report M-468, Carnegie Institute of Technology, Mar. 15, 

1945. Div. 18-101. 2-M5 

29. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads. 
Part IV — Theory of Forming Limits, Maxwell Gensamer, 
W. T. Lankford, Jr., and others, OSRD 5284, Final Report 
M-529, Carnegie Institute of Technology, June 29, 1945. 

Div. 18-101. 2-M6 

30. Plastic Flow of Aluminum Aircraft Sheet Under Combined Loads. 
Part V — Strain Distribution in Formed Parts, Maxwell Gen- 
samer, E. A. Saibel, and others, OSRD 5264, Final Report 
M-530, Carnegie Institute of Technology, June 29, 1945. 

Div. 18-101. 2-M7 

31. Beryllium- Aluminum Alloys for Engine Parts,]. G. Thompson, 
V. C. F. Holm, and others, OSRD 1656, Final Report 
M-107, National Bureau of Standards, July 29, 1943. 

Div. 18-101. 13-Ml 

32. Suggested Research on Aluminum Alloys from Members of the 
Aircraft Industry, J. C. DeHaven, OSRD 6601, Advisory 
Report M-654, National Academy of Sciences, Feb. 20, 

1946. Div. 18-101-Ml 

33. Indexing of Division 18 NDRC Reports: Reports on Aluminum 
Alloys, Helen L. Purdum, OSRD 6666, Progress Report 
M-662, National Academy of Sciences, June 15, 1946. 

Div. 18-101-M2 

34. Properties and Heat Treatment of Magnesium Alloys. Part I — 

The Effect of Size upon Tensile Properties of Specimens of Mag- 
nesium Alloy Sheet, John E. Dorn and Dan M. Finch, OSRD 
1818, Final Report M-103, University of California, Sept. 
3, 1943. Div. 18-102.1-Ml 

35. Properties and Heat Treatment of Magnesium Alloys. Part II — 

Notch Sensitivity of Magnesium Alloys, John E. Dorn and J. L. 
Meriam, OSRD 1819, Final Report M-104, University of 
California, Sept. 3, 1943. Div. 18-102.11 -Ml 

36. Properties and Heat Treatment of Magnesium Alloys. Part V — 

Section I, The Sensitivity of Magnesium Alloy Sheet to Drilled, 
Reamed and Punched Holes; Section 1 1, The Notch Sensitivity of 
Magnesium Alloy Extrusions and the Influence of Various Factors, 
John E. Dorn, Erich G. Thomsen, and Israel 1. Cornet, 
OSRD 3043, Final Report M-177, University of Cali- 
fornia, Dec. 20, 1943. Div. 18-102.11 -M2 

37. Properties and Heat Treatment of Magnesium Alloys. Part III — 
Damping Capacity of Magnesium Alloys, John E. Dorn and 
Julius J. Jelinek, OSRD 1820, Final Report M-105, Uni- 
versity of California, Sept. 3, 1943. Div. 18-102.1-M2 


38. Properties and Heat Treatment of Magnesium Alloys. Part IV — 
Heat Treatment of Magnesium Alloys, John E. Dorn, Israel 1. 
Cornet, and others, OSRD 1821, Final Report M-106, 
University of California, Sept. 3, 1943. 

Div. 18-102.1-M3 

39. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 

Properties of Magnesium Alloy Sheet, H. W. Russell, OSRD 
1146, Progress Report M-36, Battelle Memorial Institute, 
Jan. 19, 1943. Div. 18-102.12-Ml 

40. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 

Properties of Magnesium Alloy Sheet, H. W. Russell, OSRD 
1457, Progress Report M-76, Battelle Memorial Institute, 
May 17, 1943. Div. 18-102.12-M2 

41. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 

Properties of Magnesium Alloy Sheet, H. W. Russell, OSRD 
1858, Final Report M-125, Battelle Memorial Institute, 
Sept. 27, 1943. Div. 18-102.12-M3 

42. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 
Properties of Magnesium Alloy Sheet, Part I, L. R. Jackson, 
H. J. Grover, and others, OSRD 3033, Final Report 
M-169, Battelle Memorial Institute, Dec. 23, 1943. 

Div. 18-102.12-M4 

43. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 
Properties of Magnesium Alloy Sheet, Part II, L. R. Jackson, 
H. J. Grover, and others, OSRD 3792, Final Report 
M-289, Battelle Memorial Institute, June 12, 1944. 

Div. 18-102.12-M5 

44. Fatigue Properties of Magnesium Alloys and Structures. Fatigue 
Properties of Magnesium Alloy Sheet. Part HI, L. R. Jackson, 
H. J. Grover, and others, OSRD 4282, Final Report 
M-381, Battelle Memorial Institute, Oct. 20, 1944. 

Div. 18-102.12-M6 

45. Investigation of the Present Status of Magnesium Alloy Sheet in 

the Aircraft Industry, M. A. Hunter, OSRD 1726, Advisory 
Report M-121, National Academy of Sciences, Aug. 16, 
1943. Div. 18-102-Ml 

46. Physical and Stress Corrosion Properties of Magnesium Alloy 
Sheet, M. A. Hunter, OSRD 2063, Progress Report M-152, 
Rensselaer Polytechnic Institute, Nov. 25, 1943. 

Div. 18-102.1 3-Ml 

47. Physical and Stress Corrosion Properties of Magnesium Alloy 

Sheet, M. A. Hunter, A. Jones, and others, OSRD 6596, 
Final Report M-647, Rensselaer Polytechnic Institute, 
Feb. 7, 1946. Div. 18-102.4-Ml 

48. Formability of Magnesium Alloy Sheet. Part I — Elevated Tem- 
perature Variable Speed Tensile Tests on Magnesium Alloys, 
John E. Dorn and A. C. Ballaseyus, OSRD 2062, Final 
Report M-151, University of California, Nov. 19, 1943. 

Div. 18-102.2-Ml 

49. Formability of Magnesium Alloy Sheet. Part II — Forming of 
Bends on the Guerin Prm, John E. Dorn, Julius J. Jelinek, and 
A. C. Ballaseyus, OSRD 2079, Final Report M-170, 
University of California, Nov. 26, 1943. 

Div. 18-102.2-M2 

50. Formability of Magnesium Alloy Sheet. Part III — Evaluation of 

the Deep Drawing Properties of Magnesium Alloys at Elevated 
Temperatures, John E. Dorn, Dan M. Finch, and Julius J. 
Jelinek, OSRD 3350, Final Report M-210, University of 
California, Mar. 8, 1944. Div. 1 8-102. 2-M3 

51. Formability of Magnesium Alloy Sheet. Part IV — Forming 

Stretch Flanges in the Guerin Press, John E. Dorn and Erich 
G. Thomsen, OSRD 3791, Final Report M-274, Univer- 
sity of California, June 5, 1944. Div. 1 8-102. 2-M4 

52. Formability of Magnesium Alloy Sheet. Part V — Forming Shrink 
Flanges on the Guerin Prm, John E. Dorn, Erich G. Thomsen, 
and Don M. Cunningham, OSRD 3940, Final Report 
M-313, University of California, July 14, 1944. 

Div. 18-102.2-M5 


BIBLIOGRAPHY 


133 


53. Formability of Magnesium Alloy Sheet. Part VI — Forming Beads 
on the Guerin Press, Erich G. Thomsen, Don M. Cunning- 
ham, and John E. Dorn, OSRD 4042, Final Report 
M-330, University of California, Aug. 10, 1944. 

Div. 18-102.2-M6 

54. Formability of Magnesium Alloy Sheet. Part VII — Stretch Form- 

ing Magnesium Alloys, Dan M. Finch, I. G. Lotze, and John 
E. Dorn, OSRD 4171, Final Report M-353, University 
of California, Sept. 20, 1944. Div. 1 8-102. 2-M7 

55. The Effect of Combined Stresses on the Ductility of Metals, John 
E. Dorn and Erich G. Thomsen, OSRD 3218, Advisory 
Report M-213, University of California, Feb. 2, 1944. 

Div. 18-103.3-Ml 

56. Stress-Strain Relationships for Magnesium Alloy Extrusion 
under Biaxial Stresses, Don M. Cunningham, Erich G. 
Thomsen, and John E. Dorn, OSRD 4172, Report M-354, 
University of California, Sept. 20, 1944. 

Div. 18-102.13-M2 

57. Deformation Characteristics of Magnesium Alloys. Metallography 
of Commercial Magnesium Sheet, C. S. Barrett, Fred N. 
Rhines, and C. T. Haller, OSRD 3016, Progress Report 
M-189, Carnegie Institute of Technology, Dec. 9, 1943. 

Div. 18-102.3-M2 

58. Deformation Characteristics of Magnesium Alloys, C. S. Barrett, 
Fred N. Rhines, and C. T. Haller, OSRD 2076, Progress 
Report M-150, Carnegie Institute of Technology, Nov. 15, 

1943. Div. 18-102.3-Ml 

59. Deformation Characteristics of Magnesium Alloys, C. S. Barrett, 
Fred N. Rhines, and C. T. Haller, OSRD 3272, Progress 
Report M-214, Carnegie Institute of Technology, Feb. 14, 

1944. Div. 18-102. 3-M3 

60. Deformation Characteristics of Magnesium Alloys, C. S. Barrett, 
Fred N. Rhines, and C. T. Haller, OSRD 3713, Progress 
Report M-276, Carnegie Institute of Technology, May 22, 

1944. Div. 18-102.3-M4 

61. Deformation Characteristics of Magnesium Alloys, C. S. Barrett, 
Fred N. Rhines, and others, OSRD 4070, Progress Report 
M-341, Carnegie Institute of Technology, Aug. 10, 1944. 

Div. 18-102.3-M5 

62. Deformation Characteristics of Magnesium Alloys, C. S. Barrett, 
Fred N. Rhines, and others, OSRD 4653, Final Report 
M-454, Carnegie Institute of Technology, Jan. 29, 1945. 

Div. 18-102.3-M6 

63. Survey of Research on Magnesium and Magnesium Alloys Being 
Conducted by Government Agencies, Branches of the Armed 
Services, and Producers and Fabricators of Magnesium, J. C. 
DeHaven, OSRD 5400, Advisory Report M-553, National 
Academy of Sciences, Aug. 3, 1945. Div. 18-102-M2 

64. Suggested Research Topics on Magnesium and Magnesium Alloys^ 

OSRD 6599, Advisory Report M-652, National Academy 
of Sciences, P’eb. 25, 1946. Div. 18-102-M3 

65. Indexing of Division 18 NDRC Reports: Reports on Magnesium 

Alloys, Helen L. Purdum, OSRD Progress Report 

M-663, National Academy of Sciei^ffjune 15, 1946. 

Div. 18-102-M4 

66. Corrosion-Fatigue Failure of Aircraft Control Cables, Dartrey 
Lewis, A. H. Flury, Jr., and H. .J. Godfrey, OSRD 4819, 
Final Report M-467, John A. Roebling’s Sons Co., Feb. 26, 

1945. Div. 18-103.1-M5 

67. Corrosion-Fatigue Failure of Aircraft Control Cables. Effect of 

Lubrication on Fatigue Properties, Dartrey Lewis, OSRD 1 1 37, 
Progress Report M-31, John A. Roebling’s Sons Co., 
Jan. 12, 1943. Div. 18-103. 1-Ml 

68. Corrosion-Fatigue Failure of Aircraft Control Cables. Effect of 
Metallic Coatings and Lubricants on Eatigue Properties, Dartrey 
Lewis, OSRD 1525, Progress Report M-83, John A. 
Roebling’s Sons Co., June 15, 1943. Div. 18-103. 11-Ml 


69. Corrosion- Fatigue Failure of Aircraft Control Cables. The Effect 

of Sheave Diameter on the Fatigue Life of Aircraft Cables^ 
Dartrey Lewis, A. H. Flury, Jr., and H. .J. Godfrey, OSRD 
1610, Progress Report M-93, John A. Roebling’s Sons Co., 
July 1, 1943. Div. 18-103.1-M2 

70. Corrosion- Fatigue Failure of Aircraft Control Cables. The Effect 
of Metallic Coatings and Lubricants on the Fatigue and Internal 
Friction Properties of Aircraft Cables, H. J. Godfrey, A. H, 
Flury, Jr., and Dartrey Lewis, OSRD 3346, Progress Re- 
port M-207, John A. Roebling’s Sons Co., Mar. 1, 1944. 

Div. 18-103.11-M2 

71. Corrosion- Fatigue Failure of Aircraft Control Cables. Fatigue 
Tests Under Service Loads, Dartrey Lewis, A. H. Flury, Jr., 
and H. J. Godfrey, OSRD 4543, Progress Report M-439, 
John A. Roebling’s Sons Co., Dec. 29, 1944. 

Div. 18-103.1-M3 

72. Corrosion-Fatigue Failure of Aircraft Control Cables. Miscel- 
laneous Tests, H. J. Godfrey, A. H. Flury, Jr., and Dartrey 
Lewis, OSRD 4602, Progress Report M-452, John A, 
Roebling’s Sons Co., Jan. 17, 1945. Div. 18-103. 1-M4 

73. Effect of Shot Blasting on Mechanical Properties of Steel, R. L. 

Mattson and J. O. Almen, OSRD 1205, Progress Report 
M-40, Research Laboratory Division, General Motors 
Corp., Feb. 10, 1943. Div. 18-103.2-Ml 

74. Effect of Shot Blasting on Mechanical Properties of Steel, Part I, 

R. L. Mattson and J. O. Almen, OSRD 3274, Progress 
Report M-228, Research Laboratories Division, General 
Motors Corp., Feb. 19, 1944. Div. 1 8-103. 2-M2 

75. Effect of Shot Blasting on the Mechanical Properties of Steel, 
Part H, R. L. Mattson and J. O. Almen, OSRD 4825, 
Progress Report M-476, Research Laboratories Division, 
General Motors Corp., Mar. 16, 1945. Div. 18-103. 2-M3 

76. Effect of Shot Blasting on the Mechanical Properties of Steel, 
Part HI, R. L. Mattson and J. O. Almen, OSRD 6647, 
Progress Report M-661, Research Laboratories Division, 
General Motors Corp., Apr. 1, 1946. Div. 1 8-103. 2-M4 

77. Fatigue Properties of Aircraft Materials and Stiuctures, L. R. 

Jackson, H. J. Grover, and R. C. McMaster, OSRD 6600, 
Advisory Report 653, Battelle Memorial Institute, Mar. 1, 

1946. Div. 18-103.3-M2 

78. Development of armor: Report to Dr. J. B. Conant, Chairman, 

National Defense Research Committee from the ad hoc Committee 
on Armor Plate, Edgar C. Bain, Charles H. Herty, Jr., and 
others, Nov. 18, 1941. Div. 18-200-Ml 

79. Non-Ballistic Test for Armor Plate, Maxwell Gensamer, C. S. 
Barrett, and others, OSRD 2041, Final Report M-87, 
Carnegie Institute of Technology, Nov. 3, 1943. 

Div. 18-201. 1-Ml 

80. Investigation of Factors Reducing the Effective Ductility of Welded 

Steel Members, A. V. deForest and P. R. Shepler, OSRD 
4674, Final Report M-432, Massachusetts Institute of 
Technology, Feb. 6, 1945. Div. 18-602. 52-M2 

81. Direct Explosion Test for Welded Armor Plate. Part I — Develop- 

ment of Direct Explosion Test Equipment and Procedure; Part II 
— Analyses of Explosion Test Data, W. O. Snelling, G. S. 
Mikhalapov, and C. H. Jennings, OSRD 2083, Progress 
Report M-163, Trojan Powder Co. and National Academy 
of Sciences, Nov. 23, 1943. Div. 18-601. 14-M2 

82. Direct Explosion Test for Welded Armor and Ship Plate. Part I 

— Armor Plate, W. A. Snelling and W. O. Snelling, OSRD 
4655, Final Report M-446, Trojan Powder Co., Jan. 23, 
1945. Div. 18-601. 14-M3 

83. Effects of Flame Hardening on the Ballistic Properties of Pre- 

Heat-Treated Homogeneous Armor Plate, E. L. Bartholomew, 
Jr., M. S. Burton, and others, OSRD 4110, Final Report 
M-329, Massachusetts Institute of Technology, Sept. 5, 
1944. Div. 18-205-Ml 


134 


BIBLIOGRAPHY 


84. Development of a Process for Manufacturing and Welding Face 

Hardened Armor Plate, R. B. Schenck, John S. Jackson, and 
others, OSRD 3912, Final Report M-290, General Motors 
Corp., July 20, 1944. Div. 18-601. 11-M2 

85. Development of Processes for the Manufacturing and Welding of 

Case Carburized Armor Plate from Non-Alloy Steels. Part I — 
Results of Experimental Work on Prime Armor Processed from 
Plain Carbon and Low Alloy Boron Treated Steels, V. E. Hense, 
Donald P. Buswell, and R. B. Schenck, OSRD 4860, 
Final Report M-491, General Motors Corp., Mar. 24, 
1945. Div. 18-204.1-Ml 

86. Development of Processes for the Manufacturing and Welding of 
Case Carburized Armor Plate from Non- Alloy Steels. Part II — 
Results of Experimental Work on Prime Armor Processed from 
Low Alloy Boron Treated and Standard Commercial Pace Hard- 
ening Grade Steels, V. E. Hense, Donald P. Buswell, and 
R. B. Schenck, OSRD 5353, Report M-551, Buick Metal- 
lurgical Laboratory, General Motors Corp., July 19, 1945. 

Div. 18-204.1 -M2 

87. Improvement of Low Alloy Armor Steels. Part III — Control of 

Carbon in the Carburized ^one of Face Hardened Armor, C. H. 
Lorig, G. P. Krumlauf, and G. K. Manning, OSRD 1842, 
Final Report M-145, Battelle Memorial Institute, Sept. 16, 
1943. Div. 18-202-M5 

88. Improvement of Low-Alloy Armor Steels, C. H. Lorig and 

Philip C. Rosenthal, OSRD 1032, Report M-20, Battelle 
Memorial Institute, Nov. 10, 1942. Div. 18-201 -Ml 

89. Improvement of Low-Alloy Armor Steel. Literature Survey, C. H. 
Lorig, OSRD 1056, Progress Report M-25, Battelle 
Memorial Institute, Nov. 25, 1942. Div. 18-201-M2 

90. Improvement of Low Alloy Armor Steels, Philip C. Rosenthal, 
M. C. Udy, and others, OSRD 1243, Progress Report 
M-52, Battelle Memorial Institute, Mar. 1, 1943. 

Div. 18-201 -M3 

91. Improvement of Low Alloy Armor Steels, C. H. Lorig, Philip C. 
Rosenthal, and others, OSRD 1418, Progress Report M-77, 
Battelle Memorial Institute, May 13, 1943. 

Div. 18-201-M4 

92. Investigation of Boron in Armor Plate. Influence of Variations in 
Boron, Carbon and Manganese Contents on Some Properties of 
Steels for Armor Plate and Other Military Applications, Thomas 
G. Digges, OSRD 1159, Progress Report M-34, National 
Bureau of Standards, Jan. 18, 1943. Div. 18-202. 11-Ml 

93. Investigation of Boron in Armor Plate. Influence of Variations in 
Boron, Carbon and Manganese Contents on the Weldability of 
Steels for Armor Plate and Other Military Applications, Thomas 
G. Digges, OSRD 1282, Progress Report M-57, National 
Bureau of Standards, Mar. 12, 1943. Div. 18-202-M2 

94. Investigation of Boron in Armor Plate. Influence of Nitrogen on 
Some Properties of Steels with and without Boron and Titanium 
Additions, Thomas G. Digges, OSRD 1506, Progress Re- 
port M-84, National Bureau of Standards, June 3, 1943. 

Div. 18-202-M3 

95. Investigation of Boron in Armor Plate. Influence of Variations in 
Boron, Composition of Ferro-Alloys Used for Making Boron 
Additions, and Deoxidation Practice on Some Properties of Ex- 
perimental Steels Containing 0.3% Carbon and 1.6% Manganese, 
Thomas G. Digges, OSRD 1617, Progress Report M-96, 
National Bureau of Standards, July 16, 1943. 

Div. 18-202.1 1-M2 

96. Investigation of Boron in Armor Plate. Influence of Boron and 

Nickel on Some Properties of Experimental Steels Containing 0.3% 
Carbon and 0.8% Manganese, Thomas G. Digges, OSRD 
1860, Progress Report M-128, National Bureau of Stand- 
ards, Sept. 27, 1943. Div. 18-202.1 1-M3 


97. Investigation of Boron in Armor Plate. Influence of Boron and 

Chromium on Some Properties of Experimental Steels Containing 
0.3% Carbon, and 0.8% or 1.25% or 1.6% Manganese, Thomas 
G. Digges and Fred M. Reinhart, OSRD 3020, Progress 
Report M-174, National Bureau of Standards, Dec. 16, 
1943. Div. 18-202.12-Ml 

98. Investigation of Boron in Armor Plate. Influence of Nitrogen on 

Some Properties of Experimental Steels without and with Boron, 
Thomas G. Digges and Fred M. Reinhart, OSRD 3378, 
Progress Report M-231, National Bureau of Standards, 

Mar. 15, 1944. Div. 1 8-202. 12-M2 

99. Investigation of Boron in Armor Plate. Influence of Boron on Some 

Properties of Experimental Steels Containing Nickel and Chro- 
mium, Thomas G. Digges and Fred M. Reinhart, OSRD 
3769, Progress Report M-293, National Bureau of Stand- 
ards, June 10, 1944. Div. 18-202.12-M3 

100. Investigation of Boron in Armor Plate. Irifluence of Variations in 

Boron and Composition of Ferro-Alloys Used for Making Boron 
Additions on Some Properties of Basic Open Hearth Steels Con- 
taining 0.4% Carbon and 1.6% Manganese, Thomas G. 
Digges and Fred M. Reinhart, OSRD 4022, Progress Re- 
port M-336, National Bureau of Standards, Aug. 9, 1944. 

Div. 18-202.1 1-M4 

101. Investigation of Boron in Armor Plate. Influence of Boron on Some 

Properties of Experimental Steels Containing 0.3% Carbon and 
Varying Amounts of Manganese, Chromium and Molybdenum, 
Thomas G. Digges and Fred M. Reinhart, OSRD 4181, 
Final Report M-361, National Bureau of Standards, Sept. 
25, 1944. Div. 1 8-202. 12-M4 

102. Investigation of Boron in Armor Plate. Endurance Properties of 
Basic Open Hearth Steel Containing 0.4% Carbon and 1.6%o 
Manganese Without and With Boron Addition, L. R. Jackson, 
J. M. Berry, and others, OSRD 4235, Progress Report 
M-387, Battelle Memorial Institute, Oet. 10, 1944. 

Div. 18-202.1 1-M5 

103. Boron in Steel, Robert S. Archer, Edgar C. Bain, and others, 

OSRD 973, Advisory Report M-18, National Academy of 
Sciences, Nov. 3, 1942. Div. 18-202-Ml 

104. Improvement of Low Alloy Armor Steels. Part II — Boron in Steel 
of Armor Composition, C. H. Lorig, Philip C. Rosenthal, and 
M. C. Udy, OSRD 1834, Final Report M-140, Battelle 
Memorial Institute, Sept. 16, 1943. Div. 18-202-M4 

105. Improvement of Low Alloy Armor Steels. Part XVI — Study of 

the Effect of Boron on Steels Suitable for Use in Armor from 3 to 
6 Inches in Thickness, M. C. Udy, Philip C. Rosenthal, and 
others, OSRD 6294, Final Report M-619, Battelle Me- 
morial Institute, Nov. 6, 1945. Div. 18-202-M6 

106. Manufacturing and Welding of Homogeneous Armor Plate from 
Boron Treated Plain Carbon and Low Alloy Steels. Part I — 
Results of Experimental Work on Prime Homogeneous Armor, 
V. E. Hense, Donald P. Buswell, and others, OSRD 4482, 
Final Report M-431, General Motors Corp., Dec. 14, 1944. 

Div. 18-204.2-M2 

107. Manufacturing and Welding of Homogeneous Armor Plate from 

Boron Treated Plain Carbon and Low Alloy Steels. Part 1 1 — 
Results of Experimental Work on Welded Homogeneous Armor, 
V. E. Hense, S. M. Spice, and others, OSRD 5142, Final 
Report M-519, Buiek Motor Division, General Motors 
Corp., May 28, 1945. Div. 18-204.2-M3 

108. Effects of Hydrogen, Nitrogen, and Oxygen in Armor Plate: 
Literature Survey, C. H. Lorig, OSRD 1065, Progress Re- 
port M-23, Battelle Memorial Institute, Nov. 25, 1942. 

Div. 18-203-Ml 

109. Effects of Hydrogen, Nitrogen, and Oxygen in Armor Plate. Part I 
— Eractional Vacuum Fusion Analyses of Rolled and Cast Armor 
Plate Samples, C. H. Lorig, Arthur R. Elsea, and Philip C. 
Rosenthal, OSRD 1830, Final Report M-139, Battelle 
Memorial Institute, Sept. 16, 1943. Div. 18-203-M2 


CONFIDENTIAL 


BIBLIOGRAPHY 


135 


110. Effects of Hydrogen, Nitrogen, and Oxygen in Armor Plate. Part II 
— Aluminum Nitride as an Intergranular Precipitate, C. H. 
Lorig, Arthur R. Elsea, and others, OSRD 1941, Final 
Report M-153, Battelle Memoiial Institute, Oct. 19, 1943. 

^ Div. 18-203-M3 

111. Improvement oj Low Alloy Armor Steels. Part VII The Causes 
of Intergranular Fracture in Cast Armor Plate, C. H. Lorig, 
G. K. Manning, and others, OSRD 3688, Final Report 
M-286, Battelle Memorial Institute, May 18, 1944. 

Div. 18-201. 1-M2 

112. Correlation of Metallographic Structure and Hardness Limit in 

Armor Plate. Part I — Effects of Austenite Transformation Prod- 
ucts on Ballistic Properties, C. H. Lorig, Arthur R. Elsea, and 
others, OSRD 1696, Final Report M-118, Battelle Me- 
morial Institute, Aug. 5, 1943. Div. 1 8-201. 2-Ml 

113. Correlation of Metallographic Structure and Hardness Limit in 

Armor Plate. Part II — Correlation of Microstructure and Ballistic 
Properties; Part III — Analyses of Problems Presented by Indi- 
vidual Producers, C. H. Lorig, Arthur R. Elsea, and others, 
OSRD 1949, Final Report M-154, Battelle Memorial 
Institute, Oct. 19, 1943. Div. 1 8-201. 2-M2 

114. Improvement of Low Alloy Armor Steels. Part VIII Effect of 
Heat Treating Variables on the Microstructure and Mechanical 
Properties of Low Alloy Armor Steel, C. H. Lorig, Arthur R. 
Elsea, and others, OSRD 3674, Final Report M-287, 
Battelle Memorial Institute, May 18, 1944. 

Div. 18-201. 3-M4 

115. Improvement of Low Alloy Armor Steels. Part XI — Causes of 
Quench Cracking in Cast Armor Steel, M. C. Udy, M. K. 
Barnett, and others, OSRD 4667, Final Report M-465, 
Battelle Memorial Institute, Feb. 6, 1945. 

Div. 18-201. 1-M3 

116. Improvement of Low Alloy Armor Steels. Part XV — Determina- 
tion of Martensite Transformation Points, M. C. Udy, G. K. 
Manning, and others, OSRD 5028, Final Report M-511, 
Battelle Memorial Institute, Apr. 30, 1945. 

Div. 1 8-201. 2-M6 

117. Improvement of Low Alloy Armor Steels. Part XVIII — Continu- 

ation of Dilatometric Studies of Armor with Respect to Quench 
Cracking, M. C. Udy, G. K. Manning, and others, OSRD 
6296, Final Report M-621, Battelle Memorial Institute, 
Nov. 6, 1945. Div. 1 8-201. 1-M4 

118. Improvement of Low Alloy Armor Steels. Part VI — Effect of 
Melting Practice on the Properties of Armor Steel, C. H. Lorig, 
Philip C. Rosenthal, and others, OSRD 3535, Final Re- 
port M-263, Battelle Memorial Institute, Apr. 17, 1944. 

Div. 18-201. 3-M3 

119. Hardenability of Cast Steels for Use in Ordnance Materiel. Part I 

— Mechanical Properties and Hardenability of Heat Treated Cast 
Alloy Steels, C. R. Wilks, Howard S. Avery, and others, 
OSRD 5439, Final Report M-541, American Brake Shoe 
Co., Aug. 9, 1945. Div. 18-207-M5 

120. Improvement of Low Alloy Armor Steels. Part V — The Effect of 

Draw Practice on the Mechanical Properties of Six Armor Plate 
Steels, C. H. Lorig, G. P. Krumlauf, and others, OSRD 
3423, Final Report M-245, Battelle Memorial Institute, 
Mar. 30, 1944. Div. 18-201. 3-M2 

121. Improvement of Low Alloy Armor Steels. Part IV — Effect of 

Nickel on the Low Temperature Notched Bar Toughness of Low 
Alloy Armor Steels, C. H. Lorig, John G. Kura, and others, 
OSRD 3298, Final Report M-222, Battelle Memorial In- 
stitute, Feb. 19, 1944. Div. 18-201. 3-Ml 

122. Improvement of Low Alloy Steels. A Summary of the Experi- 
mental Work on Heavy Armor Steels, Philip G. Rosenthal, 
G. K. Manning, and C. H. Lorig, OSRD 4718, Progress 
Report M-480, Battelle Memorial Institute, Feb. 19, 1945. 

Div. 18-201-M5 


123. Improvement of Low Alloy Armor Steels. Part IX — Heating and 
Cooling Rates of Heavy Armor Plate and the Calibration of an 
Air-Cooled Hardenability Specimen, C. H. Lorig, John G. 
Kura, and others, OSRD 3840, Final Report M-311 
Battelle Memorial Institute, June 23, 1944. 

Div. 18-201. 3-M5 

124. Heat Treatment of National Emergency Steels for Use in Tanks, 

Combat Cars, Gun Mounts and Other Ordnance Materiel, E. W. 
Weinman and A. L. Boegehold, OSRD 3056, Progress 
Report M-180, Research Laboratories Division, General 
Motors Corp., Dec. 28, 1943. Div. 18-207-M2 

125. Heat Treatment of National Emergency Steels for Use in Tanks, 

Combat Cars, Gun Mounts and Other Ordnance Materiel, A. L. 
Boegehold and E. W. Weinman; OSRD 3743, Progress 
Report M-277, Research Laboratories Division, General 
Motors Corp., June 1, 1944. Div. 18-207-M3 

126. Heat Treatment of National Emergency Steels for Use in Tanks, 

Combat Cars, Gun Mounts, and Other Ordnance Materiel, A. L. 
Boegehold and E. W. Weinman, OSRD 1768, Progress 
Report M-126, Research Laboratories Division, General 
Motors Corp., Sept. 1, 1943. Div. 18-207-Ml 

127. Heat Treatment of National Emergency Steels for Use in Tanks, 

Combat Cars, Gun Mounts and Other Ordnance Materiel, E. W. 
Weinman and A. L. Boegehold, OSRD 4386, Final Re- 
port M-404, Research Laboratories Division, General Mo- 
tors Corp., Nov. 27, 1944. Div. 18-207-M4 

128. Improvement of Low Alloy Armor Steels. Part XIII — The 
Evaluation of Constant Temperature Transformation, Arthur R. 
Elsea, Philip G. Rosenthal, and others, OSRD 4456, Final 
Report M-427, Battelle Memorial Institute, Dec. 11, 1944. 

. Div. 1 8-201. 2-M4 

129. Improvement of Low Alloy Armor Steels. Part XIV — The Effect 

of Stress and Strain on the Isothermal Transformation of Austenite, 
Arthur R. Elsea, Philip C. Rosenthal, and others, OSRD 
4668, Final Report M-470, Battelle Memorial Institute, 
Feb. 6, 1945. Div. 18-201.2-M5 

130. Improvement of Low Alloy Armor Steels. Part XVII — A Correla- 

tion between the Predicted Microstructure and Hardness and the 
Actual Microstructure and Hardness of Various Sized Rounds and 
Plates, M. C. Udy, Arthur R. Elsea, and others, OSRD 
6295, Final Report M-620, Battelle Memorial Institute, 
Nov. 6, 1945. Div. 18-201. 3-M6 

131. Improvement of Low Alloy Armor Steels. Part XII — Mechanical 
Properties of Various Isothermally Developed Structures Compared 
with Those of Martensite Tempered to the Same Hardness, John 
G. Kura, G. K. Manning, and others, OSRD 4289, Final 
Report M-402, Battelle Memorial Institute, Oct. 26, 1944. 

Div. 1 8-201. 2-M3 

132. Effect of Alloying Elements Upon the Physical and Magnetic 

Properties of Hadfield's Steel for Armor Plate, John Chipman, 
OSRD 191, Final Report M-138, Massachusetts Institute 
of Technology, Dec. 6, 1941. Div. 18-206-Ml 

133. Non-Magnetic Steels for Armor Plate, John Chipman, A. R. 

Kaufman, and Morris Cohen, OSRD 822, Final Report 
M-14, Massachusetts Institute of Technology, Aug. 25, 
1942. Div. 18-206-M3 

134r Ballistic Tests on Some Experimental Non-Magnetic Steels for 
Armor Plate, John Chipman and A. R. Kaufman, OSRD 
480, Progress Report M-2, Massachusetts Institute of 
Technology, Mar. 10, 1942. Div. 18-206-M2 

135. Indexing of Division 18 NDRC Reports: Reports on Cast and 

Rolled Armor, Helen L. Purdum, OSRD 6595, Advisory 
Report M-646, National Academy of Sciences, Feb. 28, 

1946. Div. 18-200-M2 

136. United States Army Specification No. 57-107 A, Jan. 1, 1945. 


CONFIDENTIAL 


136 


BIBLIOGRAPHY 


137. Steel for Gun Tubes. Part IV — A Final Summary, Cyril Wells 

and Robert F. Mehl, OSRD 1329, Final Report M-62, 
OSRD 1329, Carnegie Institute of Technology, Apr. 5, 
1943. Div. 18-301-M2 

138. Improvement in \Vrought Gun Tubes. Part IV — Relation Be- 

tween Transverse Reduction of Area and Performance in Six 37- 
mm M6 Gun Tubes, Cyril Wells and Robert F. Mehl, OSRD 
6385, Final Report M-558, Carnegie Institute of Tech- 
nology, Dec. 5, 1945. Div. 18-302.6-M2 

139. Steel for Gun Tubes, Robert F. Mehl, OSRD 490, Report 
M-3, Carnegie Institute of Technology, Mar. 15, 1942. 

Div. 18-301-Ml 

140. Steel for Gun Tubes. Part II — Acceptance Tests for Wrought 

Gun Tubes, Cyril Wells and Robert F. Mehl, OSRD 1163, 
Final Report M-29, Carnegie Institute of Technology, 
Jan. 22, 1943. Div. 18-302-Ml 

141. Improvement in Wrought Gun Tubes. Part I — Operating Char- 

acteristics of Specification JVVXS-78, Vols. I and II, Cyril 
Wells, Robert F. Mehl, and others, OSRD 5420, Final 
Report M-537, Carnegie Institute of Technologv, Aug. 6, 
1945. Div. 1 8-302. 3-Ml 

142. Improvement in Wrought Gun Tubes. Part III — Linear Correla- 

tions Among the Tensile and Impact Properties in Quenched-out 
Gun Tubes, Cyril Wells, Robert F. Mehl, and others, OSRD 
5454, Final Report M-556, Carnegie Institute of Tech- 
nology, Aug. 16, 1945. Div. 1 8-302. 4-M2 

143. Improvement in Wrought Gun Tubes. Yield Strength in Wrought 

Gun Tubes, Cyril Wells and Robert F. Mehl, OSRD 1908, 
Progress Report M-146, Carnegie Institute of Technology, 
Oct. 8, 1943. Div. 18-302.6-Ml 

144. Improvement in Wrought Gun Tubes. Part VI — Effect of Reheat 

Treatment {Re quench and Draw) and Redraw on Transverse 
Ductility, Cyril Wells, Robert F. Mehl, and others, OSRD 
5476, Final Report M-562, Carnegie Institute of Tech- 
nology, Aug. 21, 1945. Div. 18-302.2-M3 

145. Improvement in Wrought Gun Tubes. Part V — Effect of Eorging 
Reduction on Average Ductility, Reduction of Area, Transverse 
and Longitudinal, Cyril Wells, C. V. Klimas, and Robert F. 
Mehl, OSRD 5455, Final Report M-561, Carnegie Insti- 
tute of Technology, Aug. 16, 1945. Div. 1 8-302. 2-M2 

146. Improvement in Wrought Gun Tubes. Part II — Effect of the Angle 
of Test on the Tensile and Impact Properties of Quenched and 
Tempered Steel Eorgings, Cyril Wells, A. H. Grobe, and 
Robert F. Mehl, OSRD 5453, Final Report M-549, 
Carnegie Institute of Technology, Aug. 16, 1945. 

Div. 18-302.4-Ml 

147. Improvement in Wrought Gun Tubes. Part VIII — Operating 
Characteristics of Specification WFAX-S8 {Complete) and Speci- 
fication WVXS-95 {Incomplete), Cyril Wells, C. V. Klimas, 
and Robert F. Mehl, OSRD 6386, Final Report M-564, 
Carnegie Institute of Technology, Dec. 5, 1945. 

Div. 18-302.3-M2 

148. Steel for Gun Tubes. Parti — The Significance of Angular Fractures, 
Robert F. Mehl and Cyril Wells, OSRD 1009, Final 
Report M-22, Carnegie Institute of Technology, Nov. 23, 
1942. 

Div. 18-301.2-Ml 

149. Steel for Gun Tubes. Part III — The Effect of Homogenization 
on the Transverse Ductility of Wrought Gun Tubes, Cyril Wells 
and Robert F. Mehl, OSRD 1207, Final Report M-43, 
Carnegie Institute of Technology, Feb. 10, 1943. 

Div. 18-302.2-Ml 

150. Improvement in Wrought Gun Tubes. Part VII — Effect of 

Upsetting on Average Transverse Ductility in Seamless Gun Tubes, 
Cyril Wells, C. V. Klimas, and Robert F. Mehl, OSRD 
5477, Final Report M-563, Carnegie Institute of Tech- 
nology, Aug. 21, 1945. Div. 1 8-302. 2-M4 


151. Improvement in Gun Steel Ingot Practices. Part I — Statistical 
and Laboratory Studies, Robert F. Mehl, J. W. Spretnak, and 
C. F. Sawyer, OSRD 4122, Final Report M-343, Carnegie 
Institute of Technology, Aug. 28, 1944. Div. 18-303-M2 

152. Improvement in Gun Steel Ingot Practices. Part II — Plant Experi- 

ments, J. W. Spretnak, C. F. Sawyer, and Robert F. Mehl, 
OSRD 5438, Final Report M-540, Carnegie Institute of 
Technology, Aug. 13, 1945. Div. 18-303-M3 

153. Improvement in Gun Steel Ingot Practice. Part III — Solidification 

of Steel Ingots, J. W. Spretnak and Robert F. Mehl, OSRD 
5919, Final Report M-557, Carnegie Institute of Tech- 
nology, Sept. 24, 1945. Div. 18-303-M4 

154. Inprovement in Gun Steel Ingot Practice. Part IV — Firing Tests 
On Seamless Gun Tubes with Bore Defects, Cyril Wells, J. W. 
Spretnak, and Robert F. Mehl, OSRD 5935, Final Report 
M-550, Carnegie Institute of Technology, Sept. 25, 1945. 

Div. 18-303-M5 

155. Improvement in Gun Steel Ingot Practice. Classification of Bore 

Defects in Seamless Gun Tubes, Robert F. Mehl, K. L. 
Fetters, and J. W. Spretnak, OSRD 5052, Revised Project 
Report M-136, Carnegie Institute of Technology, Mar. 20, 
1944. Div. 18-303-Ml 

156. Control of Basic Open Hearth Practice in Manufacture of Wrought 

Gun Tubes, W. G. Hildorf, J. G. Mravec, and John 

Welchner, OSRD 1742, Progress Report M-94, Timken 
Roller Bearing Co., Aug. 24, 1943. Div. 18-302.1-Ml 

157. Control of Basic Open Hearth Practice in Manufacture of Wrought 

Gun Tubes, W. G. Hildorf, J. G. Mravec, and John 

Welchner, OSRD 1972, Progress Report M-142, Timken 
Roller Bearing Co., Oct. 26, 1943. Div. 18-302.1-M2 

158. Control of Basic Open Hearth Melting Practice for the Manufac- 

ture of Wrought Gun Tubes,]. G. Mravec, W. G. Hildorf, and 
John Welchner, OSRD 3434, Progress Report M-229, 
Steel and Tube Division, Timken Roller Bearing Co., 
Mar. 20, 1944. Div. 18-302.1 -M3 

159. Control of Basic Open Hearth Melting Practice for the Manufac- 

ture of Wrought Gun Tubes, J. G. Mravec, John Welchner, 
and W. G. Hildorf, OSRD 4497, Final Report M-420, 
Steel and Tube Division, Timken Roller Bearing Co., 
Dec. 19, 1944. Div. 18-302.1-M4 

160. Prevention of Cracking in Gun Tubes, Cyril Wells, Robert F. 
Mehl, and others, OSRD 5383, Final Report M-555, 
Carnegie Institute of Technology, July 30, 1945. 

Div. 18-302.5-M3 

161. Investigation of the Metallo graphic and Physical Properties of New 

Types of Gun Steels, Alexander R. Troiano, OSRD 3513, 
Final Report M-239, University of Notre Dame, Apr. 10, 
1944. Div. 18-302.5-M2 

162. Time-Temperature-Hardness Relations in New Gun Steels. Time- 
Temperature-Hardness Relationships for Nine Steels, G. R. 
Fitterer and William M. O’Donnell, OSRD 5491, Final 
Report M-495, University of Pittsburgh, Aug. 27, 1945. 

Div. 18-302.5-M4 

163. Investigation of the Metallographic and Physical Properties of New 

Types of Gun Steels, Alexander R. Troiano, OSRD 1840, 
Progress Report M-130, University of Notre Dame, Sept. 
20, 1943. Div. 18-302.5-Ml 

164. Fatigue Strength of Selected Gun Steels Under Combined Stress. 
Results of Combined Bending and Torsion Fatigue Tests on SAE 
X4340 Steel, E. L. Eriksen and H. M. Hansen, OSRD 1523, 
Final Report M-61, University of Michigan, June 7, 1943. 

Div. 18-301. 1-Ml 

165. Development of High Strength Gun Steels, D. L. Edlund, OSRD 

4457, Progress Report M-434, Vanadium Corporation of 
America, Dec. 12, 1944. Div. 18-304-Ml 

166. Development of High Strength Gun Steels, D. L. Edlund and 
T. L. Oberle, OSRD 6597, Final Report M-649, Vanadi- 
um Corporation of America, Feb. 28, 1 946. Div, 1 8-304-M2 


CONFIDENTIAL 


BIBLIOGRAPHY 


137 


1 67. Indexing of Division 18 JVDRC Reports: Reports on Gun Steels, 
Katharine Forsyth, OSRD 6598, Advisory Report M-650, 
National Academy of Sciences, Feb. 28, 1946. 

Div. 18-300-Ml 

168. Investigation of the Use of Special Non- Alloy Steels for Armor- 

Piercing Capped Shot. Part I — Results of Experimental Work 
with Two Heats of Grainal Treated Carbon Steel for Production 
of 37 mm Armor Piercing Capped Shot, John S. Jackson, 
Donald P. Buswell, and others, OSRD 3110, Final Report 
M-195, Buick Motor Division, General Motors Corp., 
Jan. 10, 1944. Div. 18-401-Ml 

169. Investigation of the Use of Special Non- Alloy Steels for Armor- 
Piercing Capped Shot. Part II — Results of Experimental Work 
Directed Toward Production of a Projectile Possessing Superior 
Ballistic Properties, ]ohn S. Jackson, Donald P. Buswell, and 
others, OSRD 3583, Final Report M-256, Buick Motor 
Division, General Motors Corp., Apr. 15, 1944. 

Div. 18-401-M2 

170. Prevention of Stress-Corrosion Cracking of Cartridge Brass by 

Protective Coatings, or Surface Treatment, E. A. Anderson and 
W. M. Peirce, OSRD 3534, Final Report M-240, New 
Jersey Zinc Co., Apr. 3, 1944. Div. 1 8-402. 1-M6 

171. Prevention of Stress-Corrosion Cracking of Cartridge Brass by Pro- 

tective Coatings or Surface Treatment: Supplement to Pinal Report 
Serial No. M-240, E. A. Anderson and W. M. Peirce, OSRD 
4253, Final Report M-389, New Jersey Zinc Co., Oct. 12, 
1944. Div. 18-402. 1-M7 

172. Prevention of Stress-Corrosion Cracking of Cartridge Brass, E. A. 
Anderson, W. M. Peirce, and others, OSRD 1088, Prog- 
ress Report M-27, New Jersey Zinc Co., Dec. 10, 1942. 

Div. 18-402.1-Ml 

173. Prevention of Stress-Corrosion Cracking of Cartridge Brass by 
Protective Coatings or Surface Treatment, E. A. Anderson, 
W. M. Peirce, and others, OSRD 1262, Progress Report 
M-54, New Jersey Zinc Co., Mar. 9, 1943. 

Div. 18-402.1-M2 

174. Prevention of Stress -Corrosion Cracking of Cartridge Brass by Pro- 
tective Coatings or Surface Treatment, W. M. Peirce, E. A. 
Anderson, and others, OSRD 1440, Progress Report M-81, 
New Jersey Zinc Co., May 17, 1943. Div. 18-402. 1-M3 

175. Prevention of Stress-Corrosion Cracking of Cartridge Brass by Pro- 

tective Coatings or Surface Treatment, W. M. Peirce and E. A. 
Anderson, OSRD 1859, Progress Report M-133, New 
Jersey Zinc Co., Sept. 22, 1943. Div. 18-402. 1-M4 

176. Prevention of Stress-Corrosion Cracking of Cartridge Brass by 
Protective Coatings, or Surface Treatment, W. M. Peirce and 
E. A. Anderson, OSRD 3006, Progress Report M-176, 
New Jersey Zinc Co., Dec. 7, 1943. Div. 18-402. 1-M5 

177. Residual Stresses in Cold-Drawn Non-Ferrous Alloys. Part I — 

An X-Ray Study, H. V. Anderson and C. W. Tucker, OSRD 
1633, Final Report M-102, Lehigh University, July 28, 
1943. Div. 18-402.2-Ml 

178. Residual Stresses in Cold-Drawn Non-Ferrous Alloys. Part II — 

An X-Ray Study, C. W. Tucker, G. D. Nelson, and others, 
OSRD 3599, Final Report M-267, Lehigh University, 
May 1, 1944. Div. 18-402. 2-M2 

179. Residual Stresses in Cold-Drawn Non-Ferrous Alloys. Part III — 

An X-Ray Study, C. W. Tucker, G. D. Nelson, and H. V. 
Anderson, OSRD 4208, Final Report M-366, Lehigh Uni- 
versity, Oct. 4, 1944. Div. 1 8-402. 2-M3 

180. Residual Stresses in Cold-Drawn Non-Ferrous Alloys. Part IV — 

An X-Ray Study, C. W. Tucker, G. D. Nelson, and H. V. 
Anderson, OSRD 4475, Final Report M-423, Lehigh Uni- 
versity, Dec. 11, 1944. Div. 1 8-402. 2-M4 

181. Residual Stresses in Cold Drawn Non-Ferrous Alloys. Part V — 

An X-Ray Study, C. W. Tucker, G. D. Nelson, and H. V. 
Anderson, OSRD 4764, Final Report M-482, Lehigh Uni- 
versity, Mar. 15, 1945. Div. 1 8-402. 2-M5 


1 82. Residual Stresses in Cold-Drawn Non-Ferrous Alloys. Part VI — 

An X-Ray Study, C. W. Tucker, G. D. Nelson, and H. V. 
Anderson, OSRD 5226, Final Report M-531, Lehigh 
University, June 18, 1945. Div. 1 8-402. 2-M6 

183. Density Volume Changes Associated with Phase Changes in 
Cartridge Brass, R. L. Dowdell, OSRD 3624, Final Report 
M-217, University of Minnesota, May 13, 1944. 

Div. 18-402.3-Ml 

184. Bi-Metallic Copper-Steel Driving Bands for Projectiles. Part I — 
Experimental Driving Bands for the Naval 40 mm Projectile; 
Part II — Centrifugal Casting of Duplex Copper-Steel Tubing for 
Driving Bands, Lyall Zickrick, OSRD 3885, Final Report 
M-297, General Electric Co. Research Laboratory and 
U. S. Pipe and Foundry Co., July 11, 1944. 

Div. 18-403-Ml 

185. Bi-Metallic Copper-Steel Driving Bands for Projectiles, Part III, 
Lyall Zickrick, OSRD 5118, Final Report M-388, Gen- 
eral Electric Co. Research Laboratory, May 24, 1945. 

Div. 18-403-M2 

186. Frankford Arsenal Laboratory Report No. R-613 '‘‘"37 mm Bi- 
metallic Rotating Bandsj’’ made by General Electric Co. 
under NDRC Project NRG-60. 

187. Material and Placement of German Rotating Bands, R. T. 
Wright, U. S. Naval Technical Mission in Europe, Tech- 
nical Report 394-45, August 1945. Div. 1 8-403. 1-Ml 

188. Heat-Resisting Metals for Gas Turbine Parts, Howard C. 

Cross, OSRD 1337, Progress Report M-60, War Metal- 
lurgy Committee, Apr. 12, 1943. Div. 18-502.1 -M3 

189. Heat-Resisting Metals for Gas Turbine Parts, Howard C. 

Cross, OSRD 1871, Progress Report M-147, War Metal- 
lurgy Committee, Oct. 1, 1943. ‘ Div. 1 8-502. 1-M4 

190. Heat-Resisting Metals for Gas Turbine Parts, Howard C. 
Cross and Ward F. Simmons, OSRD 3651, Progress Re- 
port M-280, Battelle Memorial Institute, American Brake 
Shoe and Foundry Co., and others. May 10, 1944. 

Div. 18-502.1-M6 

191. Heat-Resisting Metals for Gas Turbine Parts, Howard C. 
Cross and Ward F. Simmons, OSRD 4717, Progress Re- 
port M-477, Battelle Memorial Institute, Feb. 20, 1945. 

Div. 18-502.1-M8 

192. Survey of Data on Alloys Developed for Turbosupercharger and 

Gas Turbine Applications, R. F. Miller and Howard G. Cross, 
OSRD 3042, Advisory Report M-178, American Brake 
Shoe and Foundry Co., Battelle Memorial Institute, and 
others, Dec. 27, 1943. Div. 1 8-502. 1-M5 

193. Heat-Resisting Metals for Gas Turbine Parts, Howard C. Cross 
and Ward F. Simmons, OSRD 6563, Final Report M-636, 
Battelle Memorial Institute, American Brake Shoe and 
Foundry Co., and others, Jan. 21, 1946. Div. 18-502. 1-Mll 

194. Compilation of Current Data on Selected Alloys Suitable for High 

Temperature Service in Gas Turbine and Supercharger Parts, 
Howard C. Cross, W. C. Stewart, and W. J. McCann, 
OSRD 722, Advisory Report M-12, National Academy of 
Sciences, July 22, 1942. Div. 18-502.1 -Ml 

195. Heat-Resisting Metals for Gas Turbine Parts: Experimental 
Alloys for High Temperature Service, D. L. Edlund and T. L. 
Oberle, OSRD 6564, Final Report M-657, Vanadium 
Corporation of America, Jan. 21, 1946. Div. 18-502. 1-MlO 

196. Heat-Resisting Metals for Gas Turbine Parts: Chromium Base 
Alloys, Robert M. Parke, OSRD 5044, Progress Report 
M-510, Climax Molybdenum Co., May 7, 1945. 

Div. 18-502.1 1-Ml 

197. Heat-Resisting Metals for Gas Turbine Parts: Chromium Base 

Alloys, Robert M. Parke and Alvin J. Herzig, OSRD 6547, 
Final Report M-656, Climax Molybdenum Co., Jan. 21, 
1946. Div. 18-502.11-M2 


CONFIDENTIAL 


138 


BIBLIOGRAPHY 


198. Damping Capacity of Heat-Resisting Metals for Gas Turbine 

Parts, T. E. Pochapsky and W. J. Mase, OSRD <3549, 
Progress Report M-260, Battelle Memorial Institute, Apr. 
15, 1944. Div. 18-502.12-Ml 

199. The Weldability of Heat-Resisting Alloys, A. L. Feild, F. K. 
Bloom, and G. E. Linnert, OSRD 6389, Final Report 
M-626, Rustless Iron and Steel Corp., Dec. 5, 1945. 

Div. 18-504-Ml 

200. Heat-Resisting Metals for Gas Turbine Parts, Howard C. Cross, 

OSRD 939, Progress Report M-16, War Metallurgy Com- 
mittee, Oct. 7, 1942. Div. 18-502. 1-M2 

201 . Machining Data on Heat-Resisting Metals for Gas Turbine Parts, 
Howard C. Cross, OSRD 4554, Progress Report M-451, 
Battelle Memorial Institute, Jan. 10, 1945. 

Div. 18-502.1-M7 

201a. Indexing of Division 18 NDRC Reports: Reports on Heat 
Resistant Alloys, Katharine Forsyth, OSRD 6669, Advisory 
Report M-664, National Academy of Sciences, June 15, 
1946. Div. 18-10-M3 

202. Heat-Resisting Metals for Gas Turbine Parts: A Metallurgical 
Investigation of a Large Forged Disc of Low-Carbon N- 155 Alloy, 
J. W. Freeman and Howard C. Cross, OSRD 6427, Final 
Report M-617, University of Michigan, American Brake 
Shoe and Foundry Co., and others, Aug. 4, 1945. 

Div. 18-502.1-M9 

203. Heat-Resistant Alloys for Ordnance Materiel and Aircraft and 
Naval Engine Parts. Part I — Heat-Resistant Alloys of the 21% 
Chromium — 9% Nickel Type, Howard S. Avery and Earn- 
shaw Cook, OSRD 5263, Final Report M-496, American 
Brake Shoe and Foundry Co., June 29, 1945. 

Div. 18-503-Ml 

204. Heat-Resistant Alloys for Ordnance Materiel and Aircraft and 

Naval Engine Parts. Part 1 1 — Cobalt and Nickel in 26% 
Chromium Alloys, F. S. Gardner and Howard S. Avery, 
OSRD 5334, Final Report M-516, American Brake Shoe 
and Foundry Co., July 12, 1945. Div. 18-503-M2 

205. Metal and Ceramic Materials for Jet Propulsion Devices, 
Howard C. Cross, OSRD 6571, Final Report M-648, 
Battelle Memorial Institute, Jan. 31, 1946. Div. 18-505-Ml 

206. Properties of Sheet Materials for High-Temperature Service, 
Howard C. Cross, OSRD 6602, Advisory Report M-655, 
National Academy of Sciences, Mar. 15, 1946. 

Div. 18-501-Ml 

207. Bibliography on the Damping of Metals, Howard C. Cross, 
OSRD 6603, Advisory Report M-659, Survey Project 
SP-33, National Academy of Sciences, Feb. 20, 1946. 

Div. 1 8-502. 12-M2 

208. Studies and Investigations in Connection with Research Needs in 

the Eield of Welding Ordnance Steels, R. H. Aborn and J. R. 
Stitt, OSRD 479, Progress Report M-1, Ohio State Uni- 
versity, Jan. 15, 1942. Div. 18-601-Ml 

209. Survey of Literature and Industrial Practice in the Welding of 

Armor, R. H. Aborn, H. W. Hiemke, and J. R. Stitt, OSRD 
582, Progress Report M-5, Ohio State University, Apr. 
30, 1942. Div. 18-601-M2 

210. Survey of Literature and Industrial Practice on Precipitation Hard- 

ening Alloys in Armor Welding, J. R. Stitt and William R. 
Chedsey, OSRD 770, Progress Report M-7, Ohio State 
University, July 20, 1942. Div. 18-601. 11-Ml 

211. Survey of Literature and Industrial Data on Dilation Character- 
istics of Alloy Steels Used in Ordnance and Their Significance in 
Welding, f. R. Stitt and William R. Chedsey, OSRD 771, 
Progress Report M-8, Ohio State University, July 20, 1942. 

Div. 18-601-M3 

212. Evaluation and Relief of Residual Stresses in Welded Ordnance 
Structures,]. R. Stitt and William R. Chedsey, OSRD 814, 
Progress Report M-9, Ohio State University, July 29, 1942. 

Div. 18-601. 15-Ml 


213. Weldability of Commercial Armor Plate. Part I — The Evaluation 

of Welding Procedure and Technique in Terms of Ballistic Tests; 
Part 1 1 — Investigation of the Ballistic Response of Eerritic Welds, 
G. S. Mikhalapov, R. H. Aborn, and others, OSRD 1165, 
Progress Report M-45, Federal Shipbuilding and Dry 
Dock Co., Jan. 26, 1943. Div. 18-601. 171-Ml 

214. Development of Armor Welding Electrodes: Tests of Coast Metals, 

Inc., Electrodes, Everett C. Chapman, OSRD 918, Progress 
Report M-1 5, Combustion Engineering Co., Inc., Oct. 1, 
1942. Div. 18-601. 131-Ml 

215. Armor Welding Electrodes. Part I — Development of Eerritic 
Electrodes for Welding of Armor Plate, Everett C. Chapman, 
G. S. Mikhalapov, and others, OSRD 1744, Special Prog- 
ress Report M-97, Combustion Engineering Co., Inc., and 
National Academy of Sciences, Aug. 16, 1943. 

Div. 18-601. 131-M4 

216. Armor Welding Electrodes and Weldability of Commercial Armor 
Plate. Welding of Experimental H-Plates with Manganese 
Molybdenum Electrodes, G. S. Mikhalapov, C. H. Jennings, 
and J. H. Humberstone, OSRD 3057, Advisory Report 
M-1 85, National Academy of Sciences, Dec. 30, 1943. 

Div. 18-601. 131-M6 

217. Weldability of Commercial Armor Plate, O. O. Miller, W. G. 
Benz, and others, OSRD 6567, Final Report M-642, Fed- 
eral Shipbuilding and Dry Dock Co., Jan. 15, 1946. 

Div. 18-601. 171-M6 

218. Development of Armor Welding Electrodes. Part I — Ferritic 
Electrodes for Welding Rolled Armor Plate; Part H — Eerritic 
Electrodes for Welding of Cast Armor, Everett C. Chapman 
and R. E. Lorentz, Jr., OSRD 6592, Final Report M-643, 
Combustion Engineering Co., Inc., Feb. 11, 1946. 

Div. 18-601. 131-Mll 

219. Weldability of Commercial Armor Plate. A Preliminary Investi- 

gation of Residual Stress in a Welded H-Plate, R. H. Pierce, Jr., 
W. G. Benz, and R. H. Aborn, OSRD 3348, Progress 
Report M-232, Federal Shipbuilding and Dry Dock Co., 
Mar. 8, 1944. Div. 18-601 .171-M2 

220. Weldability of Commercial Armor Plate. The Influence of Thermal 

Stress Relief on the Hardness of Eive Types of Wi” Rolled 
Armor, R. H. Aborn and R. E. Brien, OSRD 1468, Prog- 
ress Report M-73, Federal Shipbuilding and Dry Dock 
Co., May 14, 1943. Div. 18-601. 15-M2 

221. Effect of Locked Up Stresses on Ballistic Performance of Welded 
Armor. Investigation of the Stress Distribution Across the Thick- 
ness of Weld, John T. Norton, Daniel Rosenthal, and S. B. 
Maloof, OSRD 4395, Progress Report M-392, Massa- 
chusetts Institute of Technology, Nov. 24, 1944. 

Div. 18-601. 16-M2 

222. Effect of Locked Up Stresses on Ballistic Performance of Welded 
Armor, Part I, Daniel Rosenthal, J. R. Clark, and others, 
OSRD 3580, Final Report M-244, Massachusetts Insti- 
tute of Technology, Apr. 18, 1944. Div. 18-601. 16-Ml 

223. Effect of Locked Up Stresses on Ballistic Performance of Welded 
Armor, Part H, John T. Norton, Daniel Rosenthal, and S. B. 
Maloof, OSRD 4396, Final Report M-421, Massachusetts 
Institute of Technology, Nov. 24, 1944. Div. 18-601. 16-M3 

224. Development of Improved Electrode Coatings, C. B. Voldrich, 
P. J. Rieppel, and others, OSRD 4394, Progress Report 
M-371, Battelle Memorial Institute, Nov. 12, 1944. 

Div. 1 8-601. 132-Ml 

225. Development of Improved Electrode Coatings, P. J. Rieppel, 
M. W. Mallett, and others, OSRD 5101, Progress Report 
M-500, Battelle Memorial Institute, May 19, 1945. 

Div. 18-601. 132-M2 

226. Development of Improved Electrode Coatings. Part I — Eundamen- 
tals of Weld-Metal Porosity, P. J. Rieppel, M. W. Mallett, 
and others, OSRD 6549, Final Report M-627, Battelle 
Memorial Institute, Jan. 22, 1946. Div. 18-601. 132-M3 


CONFIDENTIAL 


I 


BIBLIOGRAPHY 


139 


227. Weldability of Commercial Armor Plate and Development of 

Armor Welding Electrodes. Part I — The Welding of Experi- 
mental H-Plates with NRC-2 A Type Ferritic Electrodes; Part II 
— The Welding of an M5 Tank Hull with NRC-2A Ferritic 
Electrodes, A, Muller and H. J. Zoog, OSRD 5102, Advis- 
ory Report M-507, National Academy of Sciences, May 
23, 1945. Div. 18-601. 131-M9 

228. Suggested Specification for Ferritic Armor-Welding Electrode 

Type NRC-2A, G. S. Mikhalapov andj. H. Humberstone, 
OSRD 4060, Advisory Report M-345, National Academy 
of Sciences, Aug. 17, 1944. Div. 18-601. 131-M8 

229. Weldability of Commercial Armor Plate. Isothermal Transforma- 

tion Diagram of PIRC-2A Weld Metal, O. O. Miller, F. C. 
Kristufek, and R. H. Aborn, OSRD 4478, Progress Re- 
port M-435, Federal Shipbuilding and Dry Dock Co., 
Dec. 19, 1944. Div. 18-601. 171-M4 

230. Weldability of Commercial Armor Plate. Isothermal and Cooling 

Transformation Diagrams of NRC-2A Weld Metal, O. O. 
Miller, F. C. Kristufek, and R. H. Aborn, OSRD 6586, 
Progress Report M-658, Federal Shipbuilding and Dry 
Dock Co., Feb. 6, 1946. Div. 18-601. 171-M8 

231 . Development of Armor Welding Electrodes. The Effect of Time and 
Temperature on the Physical Properties of NRC-2A Weld Metal, 
C.D. Evans, OSRD 5143, Advisory Report M-520, National 
Academy of Sciences, June 15, 1945. Div. 18-601. 131-MlO 

232. Weldability of Commercial Armor Plate. Postballistic Examina- 
tion of 0.5 Inch H-Plates Manually Welded with NRC-2A Type 
Ferritic Electrode, W. G. Benz, R. F. Campbell, and others, 
OSRD 6583, Progress Report M-635, Federal Shipbuild- 
ing and Dry Dock Co., Feb. 6, 1946. Div. 18-601.1 33-M2 

233. Weldability of Commercial Armor Plate. Investigation of Welded 
H-Plates from the 1942-1943 Canadian Cold Test. Part I — 
H-Plates, Welded by the Unionmelt Process, R. H. Aborn, 
OSRD 3514, Progress Report M-265, Federal Shipbuild- 
ing and Dry Dock Co., Apr. 20, 1944. Div. 18-601. 171 -M3 

234. Weldability of Commercial Armor Plate. Investigation of Welded 
H-Plates from the 1942-1943 Canadian Cold Test. Part II — 
H-Plates Manually Welded with Austenitic Chromium-Nickel- 
Manganese Electrodes, A. P. Gagnebin and L. L. Seigle, 
OSRD 3819, Progress Report M-298, Federal Shipbuild- 
ing and Dry Dock Co., June 14, 1944. Div. 1 8-601. 134-Ml 

235. Weldability of Commercial Armor Plate. Investigation of Welded 
H-Plates from 1942-1943 Canadian Cold Test. Part III — 
H-Plates Manually Welded with Austenitic Chromium-Nickel- 
Molybdenum Electrodes, O. O. Miller and R. H. Aborn, 
OSRD 4165, Progress Report M-369, Federal Shipbuild- 
ing and Dry Dock Co., Sept. 23, 1944. Div. 1 8-601. 134-M2 

236. Weldability of Commercial Armor Plate. Post-Ballistic Compari- 
son of Manganese- Molybdenum Ferritic Electrodes Within and 
Without the NRC-2A Specification, W. G. Benz, R. F. Camp- 
bell, and others, OSRD 6585, Progress Report M-640, 
Federal Shipbuilding and Dry Dock Co., Feb. 6, 1946. 

Div. 18-601. 133-Ml 

237. Direct Explosion Test for Welded Armor Plate, W. O. Snelling, 

OSRD 1206, Progress Report M-41, Trojan Powder Co., 
Feb. 10, 1943. Div. 18-601. 14-Ml 

238. Development of Armor Welding Electrodes. Relation of the Com- 

position of Austenitic {20 Chromium — 10 Nickel) Electrodes to 
the Physical and Ballistic Properties of Armor Weldments, A. L. 
Feild, F. K. Bloom, and G. E. Linnert, OSRD 1636, 
Progress Report M-101, Rustless Iron and Steel Corp., 
July 20, 1943. Div. 18-601. 131-M2 

239. Development of Armor Welding Electrodes. The Effect of Varia- 
tions in Chromium-Nickel Ratio and Molybdenum Content of 
Austenitic {20 Chromium — 10 Nickel) Electrodes on Properties 
of Armor Weldments, A. L. Feild, F. K. Bloom, and G. E. 
Linnert, OSRD 3034, Progress Report M-182, Rustless 
Iron and Steel Corp., Dec. 14, 1943. Div. 18-601. 131-M5 


240. Development of Armor Welding Electrodes. The Influence of the 
Type of Armor Plate on the Properties of Armor Weldments, A. L. 
Feild, F. K. Bloom, and G. E. Linnert, OSRD 3641, Final 
Report M-259, Rustless Iron and Steel Corp., May 6, 1944. 

Div. 18-601. 131-M7 

241 . Survey of Activity Relative to the Application of Large Diameter 
Austenitic Electrodes to the Welding of Armor, G. S. Mikhala- 
pov and J. H. Humberstone, OSRD 1657, Advisory Re- 
port M-109, War Metallurgy Committee, July 29, 1943. 

Div. 18-601.131-M3 

242. Non- Metallic Welding Back-Up Strips for Armor Plate Joints, 
C. R. Austin, S. L. Hoyt, and others, OSRD 2080, Prog- 
ress Report M-159, Battelle Memorial Institute, Nov. 23, 

1943. Div. 1 8-601. 12-Ml 

243. Non- Metallic Welding Back-Up Strips for Armor Plate Joints, 

S. L. Hoyt, G. B. Voldrich, and others, OSRD 3238, 

Progress Report M-200, Battelle Memorial Institute, Feb. 

7, 1944. Div. 18-601.12-M2 

244. Non- Metallic Welding Back-Up Strips for Armor Plate Joints, 
S. L. Hoyt, C. B. Voldrich, and others, OSRD 3398, 
Final Report M-220, Battelle Memorial Institute, Mar. 13, 

1944. Div. 1 8-601. 12-M3 

245. Effect of Oxygen Cutting on Weldability of Armor Plate 

F. C. Saacke, F. N. Stone, and others, OSRD 3915, 
Progress Report M-285, Air Reduction Co., Inc., June 
16, 1944. Div. 18-601. 173-Ml 

246. Effect of Oxygen Cutting on Weldability of Armor Plate, F. C. 

Saacke, C. J. Sullivan, and J. J. Crowe, OSRD 6570, 
Final Report M-633, Air Reduction Co., Inc., Jan. 29, 
1946. Div. 18-601. 173-M2 

247. Welding of Face Hardened Armor, J. K. McDowell, Paul G. 
Cunnick, and others, OSRD 4081, Final Report M-304, 
Rock Island Arsenal, Aug. 21, 1944. 

Div. 18-601.1 1-M3 

248. Stress Relief of Weldments for Machining Stability, Part I, J. R. 

Stitt, OSRD 3032, Final Report M-172, Ohio State Uni- 
versity, Dec. 22, 1943. Div. 18-601. 15-M3 

249. Stress Relief of Weldments for Machining Stability, Part H, 

J. R. Stitt, OSRD 4198, Final Report M-379, Ohio State 
University, Sept. 29, 1944. Div. 18-601. 15-M5 

250. Stress Relief of Welded Joints, Paul C. Cunnick and J. K. 

McDowell, OSRD 3406, Final Report M-230, Rock Island 
Arsenal, Mar. 15, 1944. Div. 1 8-601. 15-M4 

251. Weldability of Commercial Armor Plate. Development of Ferritic 

Weld Metal for Repair of Thick Cast Armor. Part I — Investiga- 
tion of Thirteen Preliminary Experimental Weld Metals, O. O. 
Miller, F. C. Kristufek, and R. H. Aborn, OSRD 6366, 
Progress Report M-631, Federal Shipbuilding and Dry 
Dock Go., Dec. 5, 1945. Div. 18-601. 171-M5 

252. Weldability of Commercial Armor Plate. Development of Ferritic 

Weld Metal for Repair of Thick Cast Armor. Part II — Experi- 
mental Weld Metals for Repair of 6 Inch Armor, O. O. Miller, 
F.C. Kristufek, and others, OSRD 6584, Progress Report 
M-641, Federal Shipbuilding and Dry Dock Co., Feb. 6, 
1946. Div. 18-601. 171-M7 

253. Field Service in the Welding of High-Strength Structural Steel 

and in the Repair Welding of Cast Armor, H. J. Zoog, OSRD 
6594, Advisory Report M-645, National Academy of 
Sciences, Feb. 22, 1946. Div. 18-601. 131-M12 

254. Development of Improved Electrode Coatings. Part H — Develop- 
ment of Alternating-Current Welding Electrodes for High-Strength 
Structural Use. C. B. Voldrich, D. C. Martin, and 
H. W. Russell, OSRD 6550, Final ^Report M-628, 
Battelle Memorial Institute, Jan. 22, 1946. 

Div. 1 8-601. 132-M4 


CONFIDENTIAL 


140 


BIBLIOGRAPHY 


255. Metallurgical Factors of Underbead Crackings S. L. Hoyt, C. E. 

Sims, and H. M. Banta, Technical Publication 1847, 
American Institute of Mining and Metallurgical Engi- 
neers, June 1945. Div. 18-601. 1-Ml 

256. Guide to Weldability of Steels, OSRD 1276, Report M-53, 
National Academy of Sciences, Mar. 11, 1943. 

Div. 18-60 1.1 7- Ml 

257. Evaluation of Weldability by Direct Welding Tests, G. E. Doan, 
J. H. Frye, and others, OSRD 1427, Final Report M-64, 
Lehigh University, Apr. 30, 1943. Div. 1 8-601. 172-Ml 

258. Evaluation of Weldability by Direct Welding Tests. The 

Quantitative Measurement of Welding Response by Bead Welds 
G. E. Doan, R. D. Stout, and S. S. Tor, OSRD 3537. 
Report M-201, Supplement to Final Report M-64, Lehigh 
University, Apr. 7, 1944. Div. 1 8-601. 172-M2 

259. Evaluation of Weldability by Direct Measurement of Cooling 

Rates. The Measurements of Cooling Rates Associated with Arc 
Welding and Their Application to the Selection of Optimum 
Welding Conditions, W. F. Hess, L. L. Merrill, and others, 
OSRD 1405, Final Report M-68, Rensselaer Polytechnic 
Institute, Apr. 30, 1943. Div. 18-601. 17-M2 

260. Evaluation of Weldability by Correlation of Electrical and Heat 

Constants. Determination of Cooling Curves and Analysis of Heat 
Transfer in Arc Welding of Plates, Victor Paschkis, OSRD 
1550, Final Report M-92, Columbia University, June 28, 
1943. Div. 18-601. 17-M3 

261. Evaluation of Factors Affecting Crack Sensitivity of Welded 
Joints. Part I — The Effect of Welding Variables and Restraint 
Upon the Stresses Produced in Arc Welded Joints, W. F. Hess, 
E. F. Nippes, Jr., and others, OSRD 4383, Final Report 
M-352, Rensselaer Polytechnic Institute, Nov. 13, 1944. 

Div. 1 8-601. 174-Ml 

262. Evaluation of Factors Affecting Crack Sensitivity of Welded 
Joints. Measurements of Stresses at the Threshold of Cracking 
of First Pass Weld Metal, W. F. Hess, E. F. Nippes, Jr., and 
A. P. Bunk, OSRD 4900, Final Report M-455, Rensselaer 
Polytechnic Institute, Apr. 5, 1945. Div. 18-601. 174-M2 

263. Methods of Testing Weldability of Steel Plates and Shapes, 
Part H, R. D. Stout, S. S. Tor, and others, OSRD 4529, 
Final Report M-398, Lehigh University, Jan. 2, 1945. 

Div. 18-601. 17-M4 

264. Spot Welding of Armor Plate and Low Alloy Steel. Part I — The 
Fundamentals of Spot Welding of Steel Plate, W. F. Hess, A. 
Muller, and others, OSRD 4336, Final Report M-331, 
Rensselaer Polytechnic Institute, Oct. 28, 1944. 

Div. 1 8-601. 32-Ml 

265. Spot Welding of Armor Plate and Low Alloy Steels. Part II — 
The Spot Welding of Attachments to Armor, W. F. Hess, A. 
Muller, and others, OSRD 4337, Final Report M-332, 
Rensselaer Polytechnic Institute, Oct. 28, 1944. 

Div. 1 8-601. 32-M2 

266. Radiographic and Fluoroscopic Methods of Inspection of Spot Welds 
in Aluminum Alloys, Part I, C. C. Woolsey, L. P. Gaard, and 
others, OSRD 3827, Final Report M-168, California In- 
stitute of Technology, June 20, 1944. Div. 18-601. 33-Ml 

267. Radiographic and Fluoroscopic Methods of Inspection of Spot 
Welds in Aluminum Alloys, Part H, R. C. McMaster, L. P. 
Gaard, and others, OSRD 4620, Final Report M-380, 
California Institute of Technology, Jan. 22, 1945. 

Div. 18-601. 33-M2 

268. Spot Welding of Magnesium Alloys. Part I — The Surface Treat- 

ment of Magnesium Alloy Sheet for Spot Welding, W. F. Hess, 
T. B. Cameron, and D. J. Ashcraft, OSRD 4955, Final 
Report M-374, Rensselaer Polytechnic Institute, Apr. 21, 
1945. Div. 18-601. 31-Ml 


269. Spot Welding of Magnesium Alloys. Part II — The Spot Welding 

Characteristics of Chemically Cleaned Magnesium Alloy Sheet, 
W. F. Hess, T. B. Cameron, and others, OSRD 4956, Final 
Report M-375, Rensselaer Polytechnic Institute, Apr. 21, 
1945. Div. 18-601. 31-M2 

270. Flash Welding of Alloy Steels for Ordnance, H. W. Gillett, 
C. B. Voldrich, and R. W. Bennett, OSRD 1514, Progress 
Report M-79, Battelle Memorial Institute, June 4, 1943. 

Div. 1 8-601. 22-Ml 

271. Flash Welding of Alloy Steels for Ordnance, H. W. Gillett, 
C. B. Voldrich, and R. W. Bennett, OSRD 1759, Progress 
Report M-115, Battelle Memorial Institute, Aug. 30, 1943. 

Div. 1 8-601. 22-M2 

272. Flash Welding of Alloy Steels for Ordnance, H. W. Gillett, 

C. B. Voldrich, R. W. Bennett, and P. J. Rieppel, OSRD 
3424, Progress Report M-227, Battelle Memorial Institute, 
Mar. 23, 1944. Div. 1 8-601. 22-M3 

273. Flash Welding of Alloy Steels for Ordnance, C. B. Voldrich, 
R. W. Bennett, and others, OSRD 3675, Progress Report 
M-258, Battelle Memorial Institute, Apr. 22, 1944. 

Div. 1 8-601. 22-M4 

274. Flash Welding of Alloy Steels for Ordnance, C. B. Voldrich, 
R. W. Bennett, and others, OSRD 3689, Progress Report 
M-271, Battelle Memorial Institute, May 10, 1944. 

Div. 18-601. 22-M5 

275. Flash Welding of Alloy Steels for Ordnance. Part I — Controlled 

Atmospheres, C. B. Voldrich, R. W. Bennett, and H. W. 
Gillett, OSRD 4654, Final Report M-440, Battelle Mem- 
orial Institute, Jan. 29, 1945. Div. 18-601. 22-M6 

276. Flash Welding of Alloy Steels for Ordnance. Part 1 1 — Transla- 
tion of Production Technique and Quality of Flash-Welded 
Joints'” by Hans Kilger, S. L. Hoyt, N. Baklanoff, and 
R. W. Bennett, OSRD 4786, Final Report M-458, Battelle 
Memorial Institute, Mar. 3, 1945. Div. 18-601.22-M7 

277. Non- Destructive Testing of Flashwelds, J. F. Manildi, R. C. 
McMaster, and others, OSRD 3210, Progress Report 
M-173, California Institute of Technology, Jan. 28, 1944. 

Div. 18-601.23-Ml 

278. Non- Destructive Testing of Flashwelds. Preliminary Results of 
Magnetic Retentivity Tests, J. F. Manildi, C. C. Woolsey, 
and others, OSRD 4144, Progress Report M-291, Cali- 
fornia Institute of Technology, Sept. 8, 1 944. 

Div. 1 8-601. 23-M3 

279. Non- Destructive Testing of Flashwelds. The Eddy CurrentTest, 

J. F. Manildi, R. C. McMaster, and others, OSRD 4140, 
Progress Report M-305, California Institute of Technology, 
Sept. 8, 1944. Div. 1 8-601. 23-M2 

280. Non-Destructive Testing of Flashwelds, J. F. Manildi, R. C. 
McMaster, and others, OSRD 4404, Final Report M-413, 
California Institute of Technology, Nov. 30, 1944. 

Div. 1 8-601. 23-M4 

281. Flash Welding of Aluminum, C. B. Smith, OSRD 4397, 

Advisory Report M-393, National Academy of Sciences, 
Nov. 17, 1944. Div. 18-601. 21-Ml 

282. Indexing of National Defense Research Committee Reports on 

Welding of Armor Plate, Ordnance and Structural Steels Issued 
During 1942-1944, Helen L. Purdum and Ralph H. Phelps, 
OSRD 5047, Progress Report M-481, National Academy 
of Sciences, May 9, 1945. Div. 18-600-Ml 

283. Residual Stresses in Ship Welding, E. Paul DeCarmo, Finn 
Jonassen, and J. L. Meriam, OSRD 3698, Progress Report 
M-266, University of California, May 24, 1944. 

Div. 1 8-602. 1-M2 

284. Residual Stresses in Ship Welding, E. Paul DeCarmo, J. L. 
Meriam, and Finn Jonassen, OSRD 4388, Progress Report 
M-370, University of California, Nov. 13, 1944. 

Div. 18-602.1-M3 


CONFIDENTIAL 


I 


BIBLIOGRAPHY 


141 


285. Residual Stresses in Ship Welding, E. Paul DeGarmo, Finn Jonas- 
sen, andj. L. Meriam, OSRD 3176, Progress Report M-190, 
University of California, Jan. 14, 1944. Div. 18-602. 1-Ml 

286. Residual Stresses in Ship Welding, E. Paul DeGarmo and J. L. 

Meriam, OSRD 4867, Final Report M-463, University of 
California, Mar. 29, 1945. Div. 1 8-602. 1-M5 

287. History of Residual Stresses in Welded Ships. Part I — Hulls of 

Liberty and Oil Tanker Types, E. D. Howe and A. Boodberg, 
OSRD 4866, Final Report M-445, University of Cali- 
fornia, Apr. 19, 1945. Div. 1 8-602. 1-M4 

288. History of Residual Stresses in Welded Ships. Part II — Hogging 

and Sagging Tests of Oil Tankers, M. P. O’Brien, E. D. Howe, 
and others, OSRD 5262, Final Report M-494, University 
of California, July 2, 1945. Div. 1 8-602. 1-M6 

289. History of Residual Stresses in Welded Ships. Part HI — Tests of 

Two Liberty Ships at Sea, E. D. Howe, A. Boodberg, and 
others, OSRD 6359, Final Report M-586, University of 
California, Nov. 28, 1945. Div. 1 8-602. 1-M7 

290. History of Residual Stresses in Welded Ships. Part IV — Hogging 

and Sagging Tests of Oil Tankers; and Test of C-4 Troopships, 
E. D. Howe, A. Boodberg, and M. P. O’Brien, OSRD 
6587, Final Report M-623, University of California, Feb. 
25, 1946. Div. 1 8-602. 1-M8 

291. History of Residual Stresses in Welded Ships. Part VI 1 1 — Tem- 

perature Studies of Liberty, Victory, and Refrigerated Cargo Ships, 
E. D. Howe, A. Boodberg, and M. P. O’Brien, OSRD 
6590, Final Report M-630, University of California, Feb. 
25, 1946. Div. 18-602.1-Mll 

292. History of Residual Stresses in Welded Ships. Part VI I — History 

of Deck Stresses During Construction of Victory Ships, E. D. 
Howe, A. Boodberg, and M. P. O’Brien, OSRD 6589, 
Final Report M-625, University of California, Feb. 25, 
1946. Div. 18-602.1-M10 

293. History of Residual Stresses in Welded Ships. Part VI — Heated 

Panel Welding Test, E. D. Howe, A. Boodberg, and M. P. 
O’Brien, OSRD 6588, Final Report M-624, University of 
California, Feb. 25, 1946. Div. 1 8-602. 1-M9 

294. History of Residual Stresses in Welded Ships. The Use of X-Rays 
for the Determination of Stresses in Ship Plates, M. P. O’Brien, 
Daniel Rosenthal, and others, OSRD 5060, Progress Re- 
port M-484, University of California, May 15, 1945. 

Div. 18-602.1 1-Ml 

295. History of Residual Stresses in Welded Ships. Part V — The Use 
of X-Rays or Stress Measurement on Board Ship, E. D. Howe, 
B. York, and M. P. O’Brien, OSRD 6388, Final Report 
M-609, University of California, Dec. 5, 1945. 

Div. 18-602.1 1-M2 

296. Behavior of Steel under Conditions of Multiaxial Stresses and the 
Effect of Welding and Temperature on this Behavior. Pilot Tests 
of Small Tubular Specimens, Harmer E. Davis, G. E. Troxell, 
and others, OSRD 4553, Progress Report M-405, Uni- 
versity of California, Jan. 3, 1945. Div. 1 8-602. 2-M2 

297. Study of the Behavior of Steel under Conditions of Multiaxial 
Stress and the Effect of This Behavior of Metallographic Structure 
and Chemical Composition, LeVan Griffis and G. K. Mori- 
kawa, OSRD 4793, Progress Report M-444, Illinois Insti- 
tute of Technology, Feb. 22, 1945. Div. 18-602. 21-Ml 

298. Behavior of Steel under Conditions of Multiaxial Stress and the 

Effect of this Behavior of Metallographic Structure and Chemical 
Composition, LeVan Griffis and G. K. Morikawa, OSRD 
5346, Progress Report M-490, Illinois Institute of Tech- 
nology, July 17, 1945. Div. 18-602. 21-M2 

299. Behavior of Steel under Conditions of Multiaxial Stresses and 
Effect of Welding and Temperature on This Behavior. Part I — 
Tests of Large Tubular Specimens {Ship Plate Series), Harmer 
E. Davis, G. E. Troxell, and others, OSRD 6365, Final 
Report M-542, University of California, Dec. 6, 1945. 

Div. 18-602.2-M3 


300. Behavior of Steel under Conditions of Multiaxial Stress and the 

Effect on This Behavior of Metallographic Structure and Chemical 
Composition. Tests of Small Tubular Specimens, Albert Hess, 
Carl Goodkind, and LeVan Griffis, OSRD 6593, Final 
Report M-644, Illinois Institute of Technology, Feb. 14, 
1946. Div. 18-602.21-M3 

301. Review of Literature on Behavior of Metals under Multiaxial 

Stresses, Part I, J. L. Walmsley and J. S. Marsh, OSRD 
4403, Final Report M-408, National Academy of Sciences, 
Nov. 20, 1944. Div. 18-602.2-Ml 

302. Cleavage Fracture of Ship Plate as Influenced by Design and 
Metallurgical Factors. Hatch Corner Specimen Tests, E. Paul 
DeGarmo, J. L. Meriam, and others, OSRD 5352, Prog- 
ress Report M-512, University of California, July 21, 1945. 

Div. 18-602.3-Ml 

303. Cleavage Fracture of Ship Plate as Influenced by Design and 

Metallurgical Factors. Part I — Hatch Corner Specimen Tests, 
M. P. O’Brien, E. Paul DeGarmo, and others, OSRD 
6387, Final Report M-607, University of California, Dec. 
4, 1945. Div. 18-602.3-M4 

304. Stress Analysis of Welded Sections, E. S. Jenkins, OSRD 6591, 

Advisory Report M-629, National Academy of Sciences, 
Feb. 22, 1946. Div. 18-602.4-M2 

305. Correlation of Laboratory Tests with Full Scale Ship Plate Frac- 

ture Tests, Maxwell Gensamer, T. A. Prater, and others, 
OSRD 5380, Final Report M-526, Carnegie Institute of 
Technology, July 26, 1945. Div. 18-602.3-M2 

306. Correlation of Laboratory Tests with Full Scale Ship Plate Frac- 

ture Tests, Maxwell Gensamer, T. A. Prater, and others, 
OSRD 6204, Final Report M-613, Pennsylvania State 
College, Oct. 24, 1945. Div. 18-602.3-M3 

307. Cleavage Fracture of Ship Plate as Influenced by Design and Metal- 
lurgical Factors. Part 1 1 — Flat Plate Tests, Harmer E. Davis, 
G. E. Troxell, and others, OSRD 6452, Final Report M-608, 
University of California, Jan. 10, 1946. Div. 18-602. 3-M5 

308. Cleavage Fracture of Ship Plates as Influenced by Size Effect, 

W. M. Wilson, R. A. Hechtman, and W. H. Bruckner, 
OSRD 6457, Final Report M-614, University of Illinois, 
Jan. 15, 1946. Div. 18-602.3-M6 

309. Direct Explosion Tests for Welded Armor and Ship Plate. Part 

H — Prime and Welded Plate, W. A. Snelling, and W. O. 
Snelling, OSRD 6382, Final Report M-622, Trojan Pow- 
der Co., Dec. 5, 1945. Div. 18-601. 14-M4 

310. Weldability of Steel for Hull Construction, G. E. Doan, OSRD 

6263, Final Report M-612, Lehigh University, Oct. 30, 
1945. Div. 18-602.52-M3 

311. Weldability of Steel for Hull Construction. Methods of Testing 

Weldability of Steel Plates and Shapes, R. D. Stout, S. S. Tor, 
and others, OSRD 4544, Progress Report M-414, Lehigh 
University, Dec. 27, 1944. Div. 1 8-602. 52-Ml 

312. Investigation of Metallurgical Quality of Steels Used for Hull 

Construction, H. M. Banta and Fred Dunkerley, OSRD 
5062, Progress Report M-497, Battelle Memorial Institute, 
May 14, 1945. Div. 18-602.51-Ml 

313. Investigation of Metallurgical Quality of Steels Used for Hull 

Construction, H. M. Banta, Fred Dunkerley, and others, 
OSRD 5492, Progress Report M-569, Battelle Memorial 
Institute, Aug. 24, 1945. Div. 18-602. 51-M2 

314. Investigation of Metallurgical Quality of Steels Used for Hull 

Construction, H. M. Banta, Fred Dunkerley, and others, 
OSRD 6073, Progress Report M-587, Battelle Memorial 
Institute, Oct. 14, 1945. Div. 18-602. 51 -M3 

315. Investigation of Metallurgical Quality of Steels Used for Hull 

Construction, H. M. Banta, Fred Dunkerley, and C. E. 
Sims, OSRD 6075, Final Report M-610, Battelle Mem- 
orial Institute, Oct. 14, 1945. Div. 18-602. 51-M4 


CONFIDENTIAL 


142 


BIBLIOGRAPHY 


316. Fatigue Tests of Ship Welds, S. C. Hollister and J. Garcia, 

OSRD 6544, Final Report M-606, Cornell University, 
Jan. 17, 1946. Div. 18-602.4-Ml 

317. Study of the Properties of Malleable Castings for Use in Tanks, 

Combat Vehicles, and Other Military Applications, C. H. Lorig, 
Philip C. Rosenthal, and O. W. Simmons, OSRD 1215, 
Progress Report M-47, Battelle Memorial Institute, Feb. 
16, 1943. Div. 18-701-Ml 

318. Study of the Properties of Malleable Castings for Use in Tanks, 
Combat Vehicles, and Other Military Applications, C. H. Lorig, 
Philip C. Rosenthal, and O. W. Simmons, OSRD 1589, 
Final Report M-95, Battelle Memorial Institute, July 12, 

1943. Div. 18-701-M2 

319. “Study Malleable Castings Properties for Military Appli- 
cations,” O. W. Simmons, Philip G. Rosenthal, and C. H. 
Lorig, Foundry, Vol. 71, October 1943, pp. 102-104, 190; 
November 1943, pp. 122-125, 190-192; December 1943, 
pp. 106-108, 202-204. 

320. Centrifugal Casting of Metals, A. E. Schuh, National Acad- 
emy of Sciences, 1942. Div. 18-702-Ml 

321. Bibliography on Centrifugal Casting of Metal, Howard F. 
Taylor, OSRD 1971, Final Report M-119, United States 
Naval Research Laboratory, Oct. 28, 1943. 

Div. 18-702-M7 

322. Analysis of Heat Flow in Metal Molds for Centrifugal Casting of 

Gun Tubes, Airplane Cylinders, Tank Bogey Wheels, and Other 
War Mathiel, C. H. Lorig, M. C. Udy, and H. C. Mc- 
Intyre, OSRD 1935, Final Report M-138, Battelle Mem- 
orial Institute, Oct. 12, 1943. Div. 18-702-M6 

323. Mathematics Underlying the Centrifugal Casting of Metals, A. F. 

Macconochie, W. Prager, and G. Handelman, OSRD 
1809, Advisory Report M-70, National Academy of 
Sciences, Sept. 10, 1943. Div. 18-702-M5 

324. Improvements in and Extension of Centrifugal Casting Methods 
for Production of Miscellaneous War Materiel Items, A. E. 
Schuh and Alfred Boyles, OSRD 1147, Progress Report 
M-33, United States Pipe and Foundry Co., Jan. 14, 1943. 

Div. 18-702-M2 

325. Improvement in and Extension of Centrifugal Casting Methods for 
Production of Miscellaneous War Mathiel Items, Alfred Boyles 
and A. E. Schuh, OSRD 1360, Progress Report M-63, 
United States Pipe and Foundry Co., Apr. 9, 1943. 

Div. 18-702-M3 

326. Improvements in and Extension of Centrifugal Casting Methods 

for Production of Miscellaneous War Materiel Items, OSRD 
1756, Progress Report M-120, United States Pipe and 
Foundry Co., Aug. 25, 1943. Div. 18-702-M4 

327. Improvements in and Extension of Centrifugal Casting Methods 
for Production of Miscellaneous War Materiel Items, A. E. 
Schuh and Alfred Boyles, OSRD 3584, Final Report 
M-252, United States Pipe and Foundry Co., Apr. 18, 

1944. . Div. 18-702-M8 

328. Experimental Production of Pilot Static and Centrifugal Castings 
for the Armed Services. Part I — Centrifugally Cast Composite 
Grinding Rolls, Raymond H. Schaefer, E. M. Kaulbach, 
and others, OSRD 5019, Final Report M-493, American 
Brake Shoe and Foundry Co., May 2, 1945. 

Div. 18-702-M9 

329. Experimental Production of Pilot Static and Centrifugal Castings 
for the Armed Services. Part HI — The Fluidity of Cast Alloyed 
Steels and Irons, W. S. Mott and Raymond H. Schaefer, 
OSRD 5634, Final Report M-572, American Brake Shoe 
and Foundry Co., Sept. 10, 1945. Div. 18-702-Ml 0 

330. Centrifugal and Precision Casting of Non-Ferrous Alloys. Meth- 
ods of Precision Casting of Metals, L. L. Wyman and D. 
Basch, OSRD 1844, Advisory Report M-123, National 
Academy of Sciences, Sept. 18, 1943. Div. 18-703-Ml 


331. Development and Extension of Precision Casting Methods for Pro- 

duction of Miscellaneous War Materiel Items. Part I, W. E. 
Ruder, OSRD 4398, Final Report M-242, General Elec- 
tric Co., Nov. 30, 1944. Div. 18-703-M2 

332. Development and Extension of Precision Casting Methods for Pro- 

duction of Miscellaneous War Materiel Items. Part H, L. L. 
Wyman, OSRD 4656, Final Report M-456, War Metal- 
lurgy Committee, Jan. 30, 1945. Div. 18-703-M3 

333. Experimental Production of Pilot Static and Centrifugal Castings 
for the Armed Services. Part 1 1 — Precision Casting of Gas Turbine 
Diaphragms, Raymond H. Schaefer, James L. Hall, and 
others, OSRD 5333, Final Report M-509, American Brake 
Shoe and Foundry Co., July 12, 1945. Div. 1 8-502. 13-Ml 

334. Development of a Substitute for Sillimanite as a '’'‘Wet-Patch^’' 
Material, F. H. Norton, OSRD 169, Final Report 107, 
Massachusetts Institute of Technology, Nov. 6, 1941. 

Div. 18-704.1 -Ml 

335. Development of a Substitute for Sillimanite in Pouring Rings Used 

in Special Steel Foundry Practice, F. H. Norton, OSRD 607, 
Final Report M-6, Massachusetts Institute of Technology, 
May 19, 1942. Div. 18-704.1-M2 

336. Acceptance Test for Firebrick, Pouring Box Refractories, George 

A. Bole, OSRD 189, Progress Report 134, Ohio State Uni- 
versity, Dec. 8, 1941. Div. 18-704.2-Ml 

337. Acceptance Test for Firebrick. Pouring Box Refractories, George 
A. Bole and Howard J. Orlowski, OSRD 517, Final Re- 
port M-4, Ohio State University, Mar. 16, 1942. 

Div. 18-704.2-M2 

338. Examination of Enemy Mathiel. Part I — British Sten Mark HI 
9 mm Gun, H. W. Gillett, OSRD 1138, Progress Report 
M-39, Battelle Memorial Institute, Jan. 14, 1943. 

Div. 1 8-803. 12-Ml 

339. Examination of Enemy Mathiel. Fabrication Methods Used on a 

Bimetal Driving Band on an 88 mm German Projectile and 
Copper Conservation Through the Use of Bimetal Bands, H. W. 
Gillett, OSRD 1216, Progress Report M-48, Battelle Mem- 
orial Institute, Feb. 16, 1943. Div. 18-801. 21 -Ml 

340. Examination of Enemy Mathiel. A Metallurgical Study of a 

Sample of German Surface Hardened Armor Plate, H. W. 
Gillett, OSRD 1299, Progress Report M-58, Battelle Mem- 
orial Institute, Mar. 24, 1943. Div. 1 8-801. 22-Ml 

341. Examination of Enemy Mathiel. A Metallurgical Examination 

of a German 50 mm High Explosive Round, H. W. Gillett, 
OSRD 1492, Progress Report M-88, Battelle Memorial 
Institute, June 3, 1943. Div. 18-801. 21-M2 

342. Examination of Enemy Mathiel. Chemical and Metallurgical Ex- 
amination of Three German Bomb Fragments, H. W. Gillett, 
L. H. Grenell, and others, OSRD 1499, Progress Report 
M-89, Battlle Memorial Institute, June 4, 1943. 

Div. 18-801.21-M3 

343. Examination of Enemy Mathiel. A Metallurgical Examination 
of a Japanese 75 mm High Explosive Shell, H. W. Gillett, L. H. 
Grenell, and others, OSRD 1500, Progress Report M-90, 
Battelle Memorial Institute, June 4, 1943. 

Div. 18-802.21-Ml 

344. Examination of Enemy Mathiel. A Metallurgical Examination of 
a German Gerlich Armor Piercing Shell, H. W. Gillett, L. H. 
Grenell, and others, OSRD 1561, Progress Report M-91, 
Battelle Memorial Institute, June 4, 1943. 

Div. 18-801. 21-M4 

345. Examination of Enemy Mathiel. Chemical and Metallurgical Ex- 
amination of a German Caltrop or Tire Puncture, H. W. Gillett, 
J. R. Cady, and others, OSRD 1564, Progress Report M- 
99, Battelle Memorial Institute, July 1, 1943. 

Div. 18-801. 3-Ml 


CONFIDENTIAL 


BIBLIOGRAPHY 


143 


346. Examination of Enemy Mathiel. A Metallurgical Examination 
of Two German 37 mm High Explosive Shells, H. W. Gillett, 
L. H. Grenell, and others, OSRD 1565, Progress Report 
M-lOO, Battelle Memorial Institute, July 1, 1943. 

Div. 18-801. 21-M5 

347. Examination of Enemy Materiel. Chemical and Metallurgical 
Examination of a German Needle Bearing, H. W. Gillett, J. R. 
Cady, and others, OSRD 1635, Progress Report M-108, 
Battelle Memorial Institute, July 22, 1943. 

Div. 1 8-801. 3-M2 

348. Examination of Enemy Materiel. A Metallurgical Examination of 
Miscellaneous Japanese Articles, H. W. Gillett, L. H. Grenell, 
and others, OSRD 1695, Progress Report M-116, Battelle 
Memoi'ial Institute, Aug. 8, 1943. Div. 1 8-802. 3-M2 

349. Examination of Enemy Materiel. Chemical and Metallurgical 
Examination of a Section of Japanese Body Armor, H. W. 
Gillett, J. G. Dunleavy, and others, OSRD 1694, Progress 
Report M-117, Battelle Memorial Institute, Aug. 9, 1943. 

Div. 18-802.22-Ml 

350. Examination of Enemy Materiel. A Metallurgical Examination of 
Two German 8.8 cm High Explosive Shells, H. W. Gillett, 
A. S. Henderson, and others, OSRD 1715, Progress Report 
M-122, Battelle Memorial Institute, Aug. 14, 1943. 

Div. 18-801. 21-M6 

351. Examination of Enemy Materiel. Metallurgical and Chemical Ex- 

amination of German 7.9 mm Cartridge Link Belts, H. W. 
Gillett, A. S. Henderson, and others, OSRD 1753, Prog- 
ress Report M-131, Battelle Memorial Institute, Aug. 26, 
1943. Div. 18-801. 21-M7 

352. Examination of Enemy Materiel. A Metallurgical Examination of 
a Duplex {Welded) 75 mm German AP-HE-C-BC Projectile and 
a 75 mm German H. E. Projectile Manufactured in 1942, H. W. 
Gillett, A. S. Henderson, and others, OSRD 1782, Progress 
Report M-135, Battelle Memorial Institute, Sept. 2, 1943. 

Div. 18-801. 21-M8 

353. Examination of Enemy Materiel. Metallurgical Examination of 
German Rheinmetall Aerial Bomb Fuzes, H. W. Gillett, A. S. 
Henderson, and others, OSRD 1853, Progress Report 
M-143, Battelle Memorial Institute, Sept. 20, 1943. 

Div. 18-801. 21-M9 

354. Examination of Enemy Materiel. A Survey of Various German 
Ammunition Carriers, H. W. Gillett, A. S. Henderson, and 
others, OSRD 1865, Progress Report M-144, Battelle 
Memorial Institute, Sept. 24, 1943. Div. 18-801. 21-MlO 

355. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese 37 mm Round Nose A. P. Ammunition, H. W. Gillett, 
A. S. Henderson, and others, OSRD 1942, Progress Re- 
port M-148, Battelle Memorial Institute, Oct. 12, 1943. 

Div. 18-802.21-M2 

356. Examination of Enemy Materiel. A Metallurgical Examination of 
a Track Link and Typical Bearings from German Tanks, H. W. 
Gillett, A. S. Hendeson, and others, OSRD 1963, Progress 
Report M-157, Battelle Memorial Institute, Oct. 18, 1943. 

Div. 18-801. 24-Ml 

357. Examination of Enemy Materiel. Metallurgical Study of Two 
Samples of Japanese Welded Homogeneous Light Armor, H. W. 
Gillett, A. S. Henderson, and others, OSRD 1966, Progress 
Report M-158, Battelle Memorial Institute, Oct. 18, 1943. 

Div. 18-802.22-M2 

358. Examination of Enemy Materiel. Metallurgical Examination of a 
98-K Mauser Rifle of 1941, H. W. Gillett, A. S. Henderson, 
and others, OSRD 2004, Progress Report M-164, Battelle 
Memorial Institute, Nov. 12, 1943. Div. 1 8-801. 23-Ml 

359. Examination of Enemy Materiel. Examination of French Razor 

Blade Steel, H. W. Gillett, A. S. Henderson, and others, 
OSRD 2606, Progress Report M-165, Battelle Memorial 
Institute, Nov. 12, 1943. Div. 18-803.2-Ml 


360. Examination of Enemy Materiel. Metallurgical Examination of 

Japanese Roller- Bearing Assemblies from Aircraft Engine ’‘‘‘Jekej'’ 
H. W. Gillett, A. S. Henderson, and others, OSRD 2064, 
Progress Report M-179, Battelle Memorial Institute, Nov. 
22, 1943. Div. 1 8-802. 12-Ml 

361. Examination of Enemy Materiel. Metallurgical Examination of 
German and Japanese Aluminum Ware, C. M. Craighead and 
H. W. Gillett, OSRD 3015, Progress Report M-184, 
Battelle Memorial Institute, Dec. 13, 1943. 

Div. 1 8-801. 3-M3 

362. Examination of Enemy Materiel. Metallurgical Examination of a 
German MG-34 Machine Gun of 1941, H. W. Gillett, A. S. 
Henderson, and others, OSRD 3017, Progress Report 
M-188, Battelle Memorial Institute, Dec. 13, 1943. 

Div. 1 8-801. 23-M2 

363. Examination of Enemy Materiel. A Metallurgical Examination of 

German 50 mm Mortar Shells Manufactured in 1939 and 1940, 
H. W. Gillett, A. S. Henderson, and others, OSRD 3125, 
Progress Report M-192, Battelle Memorial Institute, Jan. 
10, 1944. Div. 18-801. 21-Mll 

364. Examination of Enemy Materiel. Metallurgical and Industrial 

Examination of Two Japanese 20 mm Aircraft Mounted Machine 
Guns of 1941, H. W. Gillett, A. S. Henderson, and others, 
OSRD 3109, Progress Report M-194, Battelle Memorial 
Institute, Jan. 11, 1944. Div. 18-802.23-Ml 

365. Examination of Enemy Materiel. A Metallurgical Examination of 
Three Japanese 75 mm High Explosive Shells and Carrier, H. W. 
Gillett, A. S. Henderson, and others, OSRD 3127, Progress 
Report M-196, Battelle Memorial Institute, Jan. 10, 1944. 

Div. 18-802.21-M3 

366. Examination of Enemy Materiel. Metallurgical Examination of 
German 80 mm Mortar Shells, H. W. Gillett, A. S. Hender- 
son, and others, OSRD 3115, Progress Report M-198, 
Battelle Memorial Institute, Jan. 10, 1944. 

Div. 18-801.21-M12 

367. Examination of Enemy Materiel. Metallurgical Examination of 
an Italian 20 mm Antitank Solothurn Rifle, A. S. Henderson, 
L. H. Grenell, and others, OSRD 3126, Progress Report 
M-202, Battelle Memorial Institute, Jan. 11, 1944. 

Div. 18-803.12-M2 

368. Examination of Enemy Materiel. Metallurgical Examination of a 
6.5 mm Japanese Light Machine Gun, A. S. Henderson, L. H. 
Grenell, and others, OSRD 3116, Progress Report M-203, 
Battelle Memorial Institue, Jan. 11, 1944. 

Div. 18-802.23-M2 

369. Examination of Enemy Materiel. Corrosion Protection of Japanese 

Ordnance, A. S. Henderson, L. H. Grenell, and others, 
OSRD 3165, Progress Report M-204, Battelle Memorial 
Institute, Jan. 17, 1944. Div. 18-802. 24-Ml 

370. Examination of Enemy Materiel. A Metallurgical Examination 
of a Japanese Four-Barrel Carburetor, L. H. Grenell, A. S. 
Henderson, and others, OSRD 3182, Progress Report 
M-205, Battelle Memorial Institute, Jan. 17, 1944. 

Div. 1 8-802. 12-M2 

37 1 . Examination of Enemy Materiel. Metallurgical Examination of a 
German Pz-B. Antitank Rifle of 1941, L. H. Grenell, A. S. 
Henderson, and others, OSRD 3183, Progress Report 
M-206, Battelle Memorial Institute, Jan. 17, 1944. 

Div. 1 8-801. 23-M3 

372. Examination of Enemy Matmel. Examination of a Joint on a 
Japanese Gasoline Tank, G. O. Hoglund, G. S. Mikhalapov, 
and H. W. Gillett, OSRD 3181, Progress Report M-208, 
Battelle Memorial Institute, Jan. 22, 1944. 

Div. 1 8-802. 14-Ml 

373. Examination of Enemy Materiel. Metallurgical Examination of 
Welded Armor Plate — German PzKw HI Tank, L. H. Grenell, 
J. R. Cady, and H. W. Gillett, OSRD 3236, Progress Re- 
port M-212, Battelle Memorial Institute, Feb. 4, 1944. 

Div. 18-801. 22-M2 


CONFIDENTIAL 


144 


BIBLIOGRAPHY 


374. Examination of Enemy Materiel: A Metallurgical Study of a 
28120 mm German Gun Barrel, L. H. Grenell, J. G. Dunleavy, 
and H. W. Gillett, OSRD 3257, Progress Report M-219, 
Battelle Memorial Institute, Feb. 8, 1 944. Div. 1 8-801 .23-M4 

375. Examination of Enemy Materiel. Metallurgical Examination of 

a German 7.92 mm Semiautomatic Rifle, Gewehr 41 {W), L. H. 
Grenell, H. S. Kalish, and H. W. Gillett, OSRD 3263, 
Progress Report M-224, Battelle Memorial Institute, Feb. 
14, 1944. 18-801. 23-M6 

376. Examination of Enemy Materiel. Metallurgical Examination of a 

German Schmeizer Submachine Gun, 9 mm. Model MP-40, L. H. 
Grenell, J. R. Cady, and H. W. Gillett, OSRD 3267, 
Progress Report M-225, Battelle Memorial Institute, Feb. 
14 1944. Div. 18-801. 23-M5 

377. Examination of Enemy Materiel. Metallurgical Examination of 

Tungsten Carbide Cores from German Armor-Piercing Projectiles, 
C. A. Reichelderfer, J. M. Blalock, and others, OSRD 
3268, Progress Report M-226, Battelle Memorial In- 
stitute, Feb. 14, 1944. Div. 18-801.21-M13 

378. Examination of Enemy Materiel. Metallurgical Examination of 

a Japanese Rifle 6.5 mm {Caliber .25), 38th Tear, Pattern M1905, 

L. H. Grenell, J. R. Cady, and H. W. Gillett, OSRD 

3418 Progress Report M-235, Battelle Memorial Institute, 
Mar.’ 13, 1944. Div. 18-802.23-M3 

379. Examination of Enemy Materiel. Metallurgical Examination of 
Two German 15 cm Anticoncrete Shells and Carriers, L. H. 
Grenell, J. R. Cady, and others, OSRD 3368, Progress 
Report M-236, Battelle Memorial Institute, Mar. 13, 1944. 

Div. 18-801.21-M14 


380. Effects of Flame Hardening on the Ballistic Properties of Pre- 

Heat-Treated Homogeneous Armor Plate, E. L. Bartholomew, 
Jr., M. S. Burton, and others, OSRD 3416, Progress Re- 
port M-233, Massachusetts Institute of Technology, Mar. 
21 1944. Div. 18-204.2-Ml 

381. Examination of Enemy Materiel. Examination of Ten Rounds of 
German 20 mm H. E. Ammunition, L. H. Grenell, J. R. Cady, 
and others, OSRD 3417, Progress Report M-241, Battelle 
Memorial Institute, Mar. 21, 1944. Div. 18-801.21-M15 

382. Examination of Enemy Materiel. Metallurgical Examination of a 
' German 75 mm H. E. Hollow Charge Shell, R. M. Evans, C. A. 

Reichelderfer, and H. W. Gillett, OSRD 3538, Progress 
Report M-246, Battelle Memorial Institute, Apr. 8, 1944. 

Div. 18-801. 21-M16 

383. Examination of Enemy Materiel. Metallurgical Examination of 

German Armor Piercing Tungsten Carbide Rounds of 28120, 37, 
and 50 mm Calibers, L. H. Grenell, J. R. Cady, and others, 
OSRD 3536, Progress Report M-248, Battelle Memorial 
Institute, Apr. 14, 1944. Div. 18-801. 21-M17 

384. Examination of Enemy Materiel. Metallurgical Examination of a 
Series of Six 7.9 mm MG-17 German Aircraft Gun Barrels, 1937- 

1942, and Four 13 to 20 mm, L. H. Grenell, J. R. Cady, and 
others, OSRD 3548, Progress Report M-250, Battelle 
Memorial Institute, Apr. 14, 1944. Div. 1 8-801. 23-M7 

385. Examination of Enemy Materiel. Metallurgical Examination of 
' German 50 mm A.P.-H.E. {Monobloc) Shells with Long and 

Short Cartridge Cases, L. H. Grenell, J. R. Cady, and others, 
OSRD 3586, Progress Report M-253, Battelle Memorial 
Institute, Apr. 24, 1944. Div. 18-801.2DM18 

386. Examination of Enemy Materiel. Metallurgical Examination of a 

Japanese Aircraft Exhaust Stack and Collector Ring, C. E. 
Levoe, Howard C. Cross, and H. W. Gillett, OSRD 3587, 
Progress Report M-254, Battelle Memorial Institute, Apr. 
24^ 1 944. Div. 1 8-802. 1 2-M3 

387. Examination of Enemy Materiel. Metallurgical Examination of 
’ German and Italian 20 mm Armor Piercing Ammunition 1938- 

1943, ]. R. Cady, L. H. Grenell, and H. W. Gillett, OSRD 

3588 Progress Report M-261, Battelle Memorial Institute, 
Apr.^24, 1944. Div. 18-801. 21-M19 


388. Examination of Enemy Materiel. Metallurgical Examination of 
German 50 mm H.E. Shells with Long and Short Cartridge Cases, 

L. H. Grenell, J. R. Cady, and others, OSRD 3585, Prog- 
ress Report M-262, Battelle Memorial Institute, Apr. 24, 
1944. Div. 18-801.21-M20 

389. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese Rifle 7.7 mm {Caliber .303"), Model 99, L. H. 
Grenell, J. R. Cady, and others, OSRD 3625, Progress 
Report M-268, Battelle Memorial Institute, May 2, 1944. 

Div. 18-802.23-M5 

390. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese 50 mm Grenade Discharger, L. H. Grenell, J. R. 
Cady, and H. W. Gillett, OSRD 3623, Progress Report 
M-269, Battelle Memorial Institute, May 2, 1944. 

Div. 18-802.23-M4 

391. Examination of Enemy Materiel. Analysis of Captured Japanese 

Ethyl Fluid, C. M. Gambrill, C. T. Leacock, and M. Sue 
Aydelott, OSRD 3703, Progress Report M-275, The Ethyl 
Corp., May 31, 1944. Div. 1 8-802. 14-M2 

392. Examination of Enemy Materiel. Metallurgical Examination of 

German 50 mm APC-HE Rounds with Long and Short Cartridge 
Cases, L. H. Grenell, J. R. Cady, and others, OSRD 3636, 
Progress Report M-281, Battelle Memorial Institute, May 
10, 1944. Div. 18-801. 21-M21 

393. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese 7.7 mm Model 92 Heavy Machine Gun of 1938, J. R. 
Cady, L. H. Grenell, and others, OSRD 3643, Progress 
Report M-282, Battelle Memorial Institute, May 15, 1944. 

Div. 18-802.23-M6 

394. Examination of Enemy Materiel. Metallurgical Examination of 

Sections of 15, 30, and 50 Kilogram Japanese Antipersonnel 
Bombs, L. H. Grenell,.}. R. Cady, and others, OSRD 3661, 
Progress Report M-283, Battelle Memorial Institute, May 
15, 1944. Div. 18-802. 21-M4 

395. Examination of Enemy Materiel. Metallurgical Examination of 
Four German Duplex Welded 37 mm A. P. Rounds and 3 German 
37 mm A.P.-H.E. Projectiles, L. H. Grenell, J. G. Dunleavy, 
and H. W. Gillett, OSRD 3665, Progress Report M-284, 
Battelle Memorial Institute, Mav 15, 1944. 

Div. 1 8-801. 21-M22 

396. Examination of Enemy Materiel. Metallurgical Examination of 

One 120 mm Japanese High-Explosive Naval Projectile and 3 
Fuses, L. H. Grenell, J. R. Cady, and others, OSRD 3745, 
Progress Report M-294, Battelle Memorial Institute, 
June 2, 1944. Div. 18-802.21-M5 

397. Examination of Enemy Materiel. Metallurgical Examination of 
Six Rounds of Japanese 20 mm H.E. Ammunition, L. H. Grenell, 
J. R. Cady, and others, OSRD 3746, Progress Report M- 
295, Battelle Memorial Institute, June 2, 1944. 

Div. 18-802.21-M6 

398. Examination of Enemy Materiel. Metallurgical Examination of 
Two German 10.5 cm A.P.C., B.C. Rounds, L. H. Grenell, 
J. R. Cady, and others, OSRD 3716, Progress Report 
M-296, Battelle Memorial Institute, June 2, 1944. 

Div. 18-801.21-M23 

399. Examination of Enemy Materiel. Metallurgical Examination of 
German 20 mm MG-151 Mauser Aircraft Machine Gun, L. H. 
Grenell, J. R. Cady, and others, OSRD 3818, Progress Re- 
port M-299, Battelle Memorial Institute, June 20, 1944. 

Div. 1 8-801. 23-M8 

400. Examination of Enemy Materiel. Metallurgical Examination of 
a Japanese 1 jS Kg Anti-Parked Aircraft Bomb, L. H. Grenell, 
J. R. Cady, and others, OSRD. 3814, Progress Report 
M-300, Battelle Memorial Institute, June 14, 1944. 

Div. 18-802.21-M7 


BIBLIOGRAPHY 


145 


401. Examination of Enemy Materiel. Metallurgical Examination of 
Two Japanese 80 mm High-Explosive Naval Projectiles, L. H. 
Grenell, J. R. Cady, and others, OSRD 3813, Progress 
Report M-301, Battelle Memorial Institute, June 14, 1944. 

Div. 18-802.21-M8 

402. Examination of Enemy Materiel. Metallurgical Examination of 

Two Japanese Oxygen Cylinders, H. L. Anthony, OSRD 3812, 
Progress Report M-303, Mellon Institute of Industrial 
Research, June 14, 1944. Div. 1 8-802. 15-Ml 

403. Examination of Enemy Mathiel. Metallurgical Examination of 
a Japanese Naval Aircraft Gear Oil Pump, L. H. Grenell, J. R. 
Cady, and others, OSRD 3836, Progress Report M-307, 
Battelle Memorial Institute, June 1 9,1 944. Div. 1 8-802. 12-M5 

404. Examination of Enemy Mathiel. Metallurgical Examination of 
Three Types of Japanese Aircraft Exhaust Valves and Two Types 
of Intake Valves, C. E. Levoe, Howard C. Cross, and H. W. 
Gillett, OSRD 3838, Progress Report M-308, Battelle 
Memorial Institute, June 19, 1944. Div. 1 8-802. 12-M4 

405. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese 63 Kilogram Bombs, Fuzes, and Gaines, L. H. Grenell, 
y R. Cady, and others, OSRD 3839, Progress Report 
M-309, Battelle Memorial Institute, June 19, 1944. 

Div. 18-802.21-M9 

406. Examination of Enemy Mathiel. Metallurgical Examination of 
Six Rounds of Japanese 20 mm AP Ammunition, L. H. Grenell, 
J. R. Cady, and others, OSRD 3843, Progress Report 
M-310, Battelle Memorial Institute, June 27, 1944. 

Div. 18-802.21-M10 

407. Examination of Enemy Mathiel. Metallurgical Examination of 

Japanese 25 mm Hotchkiss Incendiary and H.E. Incendiary, 
Tracer Rounds, L. H. Grenell, J. R. Cady, and others, 
OSRD 3844, Progress Report M-314, Battelle Memorial 
Institute, July 3, 1944. Div. 18-802. 21-Ml 1 

408. Examination of Enemy Mathiel. Metallurgical Examination of a 
Japanese Sakae-12 Engine Oil Tank, L. H. Grenell, J. R. 
Cady, and others, OSRD 3845, Progress Report M-315, 
Battelle Memorial Institute, July 3, 1944. 

Div. 18-802.12-M6 

409. Examination of Enemy Mathiel. Metallurgical Examination of 
Czechoslovakian Tank Armor Plate, L. H. Grenell, J. R. Cady, 
and others, OSRD 3846, Progress Report M-316, Battelle 
Memorial Institute, July 3, 1944. Div. 18-803. 11-Ml 

410. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese 70 mm and 75 mm H.E. Ammunition, L. H. Grenell, 
J. R. Cady, and others, OSRD 3894, Progress Report 
M-318, Battelle Memorial Institute, July 11, 1944. 

Div. 18-802.21-M14 

411. Examination of Enemy Mathiel. Metallurgical Examination of 
Four Japanese 50 mm Grenades and Six Fuzes, L. H. Grenell, 
J. R. Cady, and others, OSRD 3895, Progress Report 
M-319, Battelle Memorial Institute, July 11, 1944. 

Div. 18-802.21-M13 

412. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese 37 mm High Explosive Shells, L. H. Grenell, J. R. 
Cady, and others, OSRD 3896, Progress Report M-320, 
Battelle Memorial Institute, July 11, 1944. 

Div. 18-802.21-M12 

413. Examination of Enemy Mathiel. Metallurgical Examination and 

Performance Tests of a Japanese Tokogawa Aircraft Magnet, 
L. H. Grenell, J. R. Cady, and others, OSRD 3891, 
Progress Report M-322, Battelle Memorial Institute, 
July 11, 1944. Div. 1 8-802. 12-M7 

414. Examination of Enemy Mathiel. Metallurgical Examination of a 

Japanese Navy 7 KVA Alternating Current Generator Repair Kit, 
L. H. Grenell, J. R. Cady, and others, OSRD 3892, 
Progress Report M-323, Battelle Memorial Institute, 
July 11, 1944. Div. 18-802. 3-M3 


415. Examination of Enemy Mathiel. Metallurgical Examination of 

Armor Plate from Japanese Type I F ’’’’Oscar''' Mark II SE 
Fighter, L. H. Grenell, J. R. Cady, and others, OSRD 3893, 
Progress Report M-324, Battelle Memorial Institute, 
July 11, 1944. Div. 18-802.1 1-Ml 

416. Examination of Enemy Mathiel. A Aletallurgical Examination of 

Two Japanese 7.7 mm Aircraft Machine Guns of 1938 and 1942, 
E. W. Ganslein, C. A. Reichelderfer, and others, OSRD 
3917, Progress Report M-325, Battelle Memorial Institute, 
July 18, 1944. Div. 18-802.23-M7 

417. Examination of Enemy Mathiel. A Metallurgical Examination of 
Three 40 mm Japanese Naval Projectiles, L. H. Grenell, J. R. 
Cady, and others, OSRD 3918, Progress Report M-326, 
Battelle Memorial Institute, July 18, 1944. 

Div. 18-802.21-M15 

418. Examination of Enemy Mathiel. A Aletallurgical Examination of 

Japanese .30 Caliber and .50 Caliber Disintegrating Cartridge 
Link Belts, L. H. Grenell, J. R. Cady, and others, OSRD 
3919, Progress Report M-327, Battelle Memorial Institute, 
July 18, 1944. Div. 18-802.21-M16 

419. Examination of Enemy Alathiel. Metallurgical Examination of a 
Japanese Aircraft Oil Radiator, L. H. Grenell, J. R. Cady, 
and others, OSRD 3920, Progress Report M-333, Battelle 
Memorial Institute, July 18, 1944. Div. 1 8-802. 12-M8 

420. Examination of Enemy Mathiel. Metallurgical Examination of 

Selected Parts from Japanese Type 100, Radial, 1450 H.P., 
Aircraft Engines, L. H. Grenell, J. R. Cady, and others, 
OSRD 3921, Progress Report M-334, Battelle Memorial 
Institute, July 21, 1944. Div. 18-802.12-M10 

421. Examination of Enemy Mathiel. Design Features and Perform- 
ance Characteristics of the Japanese Hand and Electric Inertia 
Starter, R. M. Nardone, OSRD 3922, Progress Report 
M-337, Battelle Memorial Institute, July 20, 1944. 

Div. 1 8-802. 12-M9 

422. Examination of Enemy Mathiel. Metallurgical Examination of 

Japanese 81 mm High Explosive Light Mortar Shell Complete 
with Type 93 Fuze, L. H. Grenell, J. R. Cady, and others, 
OSRD 3966, Progress Report M-339, Battelle Memorial 
Institute, July 27, 1944. Div. 18-802.21-M17 

423. Examination of Enemy Mathiel. Metallurgical Examination of a 
Japanese Sakae-12 Aircraft Engine Mount, L. H. Grenell, 
J. R. Cady, and others, OSRD 3967, Progress Report 
M-340, Battelle Memorial Institute, July 27, 1944. 

Div. 18-802.12-Mll 

424. Examination of Enemy Mathiel. Metallurgical Examination of 

Fuel Tank from Japanese Aircraft ’’Oscar," C. A. Reichel- 
derfer, J. M. Blalock, and H. W. Gillett, OSRD 3999, 
Progress Report M-344, Battelle Memorial Institute, 
Aug. 7, 1944. Div. 1 8-802. 14-M3 

425. Examination of Enemy Mathiel. Metallurgical Investigation of 

German 170 mm Gun Tube, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 4000, Progress Report 
M-346, Massachusetts Institute of Technology, Aug. 7, 
1944. Div. 18-801. 23-M9 

426. Examination of Enemy Mathiel. Metallurgical and Chemical 
Examination of a Japanese Landing Gear and Wheel, L. H. 
Grenell, J. R. Cady, and others, OSRD 4001, Progress 
Report M-347, Battelle Memorial Institute, Aug. 9, 1944. 

Div. 18-802. 11 -M2 

427. Examination of Enemy Mathiel. Metallurgical Examination of 

Four Japanese 47 mm Armor Piercing, High Explosive Shells, 
L. H. Grenell, J. R. Cady, and others, OSRD 4062, 
Progress Report M-349, Battelle Memorial Institute, Aug. 
22,^944. Div. 18-802.21-M18 

428. Examination of Enemy Mathiel. Metallurgical Examination of 
Parts from a Japanese Sakae-12 Engine, L. H. Grenell, J. R. 
Cady, and others, OSRD 4063, Progress Report M-350, 
Battelle Memorial Institute,Aug.22,1944.Div. 18-802. 12-M12 


L 


146 


BIBLIOGRAPHY 


429. Examination of Enemy AlaterieL Metallurgical Examination of a 
Japanese 20 mm Aircraft Machine Gun, L. H. Grenell, J. R. 
Cady, and others, OSRD 4064, Progress Report M-351, 
Battelle Memorial Instutite, Aug. 22, 1944. 

Div. 18-802.23-M8 

430. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Army 105 mm H.E. Shell of 1938, L. H. Grenell, 
J. R. Cady, and others, OSRD 4071, Progress Report 
M-355. Battelle Memorial Institute, Aug. 24, 1944. 

Div. 18-802.21-M19 

431. Examination of Enemy Materiel. Metallurgical Examination of a 
German Airspeed Indicator, L. R. Jackson, W. W. Beaver, 
and H. W. Gillett, OSRD 4072, Progress Report M-356, 
Battelle Memorial Institute, Aug. 24, 1 944. Div. 1 8-801 . 2-Ml 

432. Examination of Enemy Mathiel. Metallurgical Examination of 
Landing Gear Strut, Landing Wheel, and Tail Wheel Strut 
Assembly from Japanese Aircraft Betty,'' C. A. Reichelderfer, 
J. M. Blalock, and others, OSRD 4073, Progress Report 
M-357, Battelle Memorial Institute, Aug. 24, 1944. 

Div. 18-802.1 1-M3 

433. Examination of Enemy Alathiel. Metallurgical Examination of a 
German and a Japanese Altimeter, L. R. Jackson, W. W. 
Beaver, and H. W. Gillett, OSRD 4113, Progress Report 
M-358, Battelle Memorial Institute, Sept. 7, 1944. 

Div. 1 8-801. 12-M3 

434. Examination of Enemy Materiel. Metallurgical Examination of 

Japanese 75 mm Armor-Piercing, High Explosive Howitzer 
Rounds, L. H. Grenell, J. R. Cady, and H. W. Gillett, 
OSRD 4089, Progress Report M-359, Battelle Memorial 
Institute, Aug. 29, 1944. Div. 1 8-802.21 -M20 

435. Examination of Enemy Materiel. Metallurgical Examination of 

a German Aircraft Master Compass and a Pilot {Repeater) Com- 
pass, L. R. Jackson, W. W. Beaver, and H. W. Gillett, 
OSRD 4090, Progress Report M-360, Battelle Mem- 
orial Institute, Aug. 29, 1944. Div. 1 8-801. 12-M2 

436. Examination of Enemy AlaterieL Metallurgical Examination of 
Four Different Types of Japanese Aircraft Spark Plugs, L. H. 
Grenell, J. R. Cady, and others, OSRD 4125, Progress 
Report M-362, Battelle Memorial Institute, Sept. 7, 1944. 

Div. 18-802.12-M13 

437. Examination of Enemy Materiel. Metallurgical Examination of 

Captured Enemy Pressure Vessels, H. L. Anthony, OSRD 4126, 
Progress Report M-363, Mellon Institute of Industrial 
Research, Sept. 7, 1944. Div. 1 8-801. 13-Ml 

438. Examination of Enemy Materiel. Metallurgical Investigation of 
Two 50 mm German Tank Gun Tubes, Breech Rings and Breech 
Ring Locking Collars, E. L. Bartholomew, Jr., M. S. Burton, 
and F. R. Evans, OSRD 4135, Progress Report M-364, 
Battelle Memorial Institute, Sept. 12, 1944. 

Div. 18-801. 23-MlO 

439. Examination of Enemy Materiel. Metallurgical Examination of 

Two Japanese Aircraft Bank and Turn Indicators, L. R. Jack- 
son, W. W. Beaver, and H. W. Gillett, OSRD 4127, 
Progress Report M-367, Battelle Memorial Institute, 
Sept. 7, 1944. Div. 18-802.1 3-Ml 

440. Examination of Enemy Materiel. Luminescence of Enemy Aircraft 
Instrument Dials,]. R. Devore, OSRD 4145, Progress Re- 
port M-368, New Jersey Zinc Co., Sept. 7, 1944. 

Div. 1 8-802. 13-M2 

441. Examination of Enemy Materiel. Metallurgical Examination of 
Two Japanese 140 mm Naval Projectiles, L. H. Grenell, J. R. 
Cady, and others, OSRD 4131, Progress Report M-372, 
Battelle Memorial Institute, Sept. 14, 1944. 

Div. 18-802.21-M21 


442. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese Aircraft 12.7 mm Browning" Machine Gun, L. H. 
Grenell, J. R. Cady, and others, OSRD 4178, Progress 
Report M-376, Battelle Memorial Institute, Sept. 25, 1944. 

Div. 18-802.23-M9 

443. Examination of Enemy Matmel. Metallurgical Examination of 

Airframe Sections from ^'‘Jeke," ‘‘Waif' “Lily," and “Dinah" 
Japanese Planes, L. H. Grenell, J. R. Cady, and others, 
OSRD 4179, Progress Report M-377, Battelle Memorial 
Institute, Sept. 25, 1944. Div. 18-802.1 1-M4 

444. Examination of Enemy Materiel. Examination of Diaphragm and 
Gasket from Japanese Aircraft Fuel Pump, R. G. Chollar, 
F. C. Croxton, and H. W. Gillett, OSRD 4180, Progress 
Report M-378, Battelle Memorial Institute, Sept. 26, 1944. 

Div. 1 8-802. 14-M4 

445. Examination of Enemy Materiel. Metallurgical Examination of 
Two German MG-151 Aircraft Machine Gun Mounts, L. H. 
Grenell, J. R. Cady, and others, OSRD 4214, Progress 
Report M-383, Battelle Memorial Institute, Oct. 7, 1944. 

Div. 1 8-801. 23-Mll 

446. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese Sakae-21 Aircraft Engine, L. H. Grenell, J. R. Cady, 
and H. W. Gillett, OSRD 4234, Progress Report M-384, 
Battelle Memorial Institute, Oct. 7, 1944. 

Div. 18-802.12-M14 

447. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese “ Jeke" Aircraft Volt Box, L. H. Grenell, J. R. Cady, 
and others, OSRD 4215, Progress Report M-386, Battelle 
Memorial Institute, Oct. 7, 1944. Div. 18-802. 12-M15 

448. Examination of Enemy Materiel. Metallurgical Investigation of 
German 105 mm Gun Tube, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 4251, Progress Report 
M-390, Battelle Memorial Institute, Oct. 7, 1944. 

Div. 18-801. 23-M12 

449. Examination of Enemy Mathiel. Metallurgical Examination of 

Airframe Sections from Japanese Aircraft “Jill," C. E. Heuss- 
ner, A. B. Westerman, and H. W. Gillett, OSRD 4252, 
Progress Report M-391, Battelle Memorial Institute, 
Oct. 7, 1944. Div. 18-802.1 1-M5 

450. Examination of Enemy Materiel. Metallurgical Examination of 

Japanese Oxygen and Carbon Dioxide Cylinders, H. L. Anthony, 
OSRD 4267, Progress Report M-394, Battelle Memorial 
Institute, Oct. 17, 1944. Div. 1 8-802. 15-M2 

451. Examination of Enemy Mathiel. Metallurgical Examination of 
Oil Cooler from Japanese Aircraft “Betty," E. M. Smith, B. D. 
Gonser, and H. W. Gillett, OSRD 4279, Progress Report 
M-395, Battelle Memorial Institute, Oct. 17, 1944. 

Div. 18-802.12-M16 

452. Examination of Enemy Materiel. Examination of Japanese Air- 
craft Tires and Tubes, OSRD 4280, Progress Report M-396, 
Battelle Memorial Institute, Oct. 17, 1944. 

Div. 18-802.1 1-M6 

453. Examination of Enemy Matmel. Metallurgical Examination of a 

German and a Japanese Aircraft Rate of Climb Indicator, L. R. 
Jackson, W. W. Beaver, and H. W. Gillett, OSRD 4281, 
Progress Report M-397, Battelle Memorial Institute, 
Oct. 17, 1944. Div. 1 8-801. 12-M4 

454. Examination of Enemy Materiel. Metallurgical Examination of 
a German Aircraft Course Meter, L. R. Jackson, W. W. Beaver, 
and H. W. Gillett, OSRD 4315, Progress Report M-399, 
Battelle Memorial Institute, Nov. 8, 1944. 

Div. 18-801. 12-M5 

455. Examination of Enemy Materiel. Corrosion Resistance of a Steel 

Piston and a Magnesium Casting from a Japanese Oleo Landing 
Strut, L. H. Grenell, J. R. Cady, and others, OSRD 4316, 
Progress Report M-400, Battelle Memorial Institute, 
Nov. 8, 1944. Div. 1 8-802. 11-M7 


CONFIDENTIAL 


BIBLIOGRAPHY 


147 


456. Examination of Enemy Alatenel. Metallurgical Examination of 
Six German Explosive Bomb Rack Bolts, L. H. Grenell, J. R. 
Cady, and others, OSRD 4317, Progress Report M-401, 
Battelle Memorial Institute, Nov. 8, 1944. 

Div. 1 8-801. 13-M2 

457. Examination of Enemy Materiel. Metallurgical Examination of 
a German MG-42, 7.92 mm Machine Gun, L. H. Grenell, J. R. 
Cady, and others, OSRD 4358, Progress Report M-403, 
Battelle Memorial Institute, Nov. 13, 1944. 

Div. 18-801. 23-M13 

458. Examination of Enemy Alathiel. Metallurgical Examination of 
Six Grades of Swedish Carbide Tool Tips, S. L. Hoyt, E. B. T. 
Kindquist, and H. W. Gillett, OSRD 4387, Progress Re- 
port M-410, Battelle Memorial Institute, Nov. 13, 1944. 

Div. 18-803.2-M2 

459. Examination of Enemy Alatenel. Metallurgical Examination of 
Parts from an Aichi V-1 2 Japanese Aircraft Engine, L. H. Gren- 
ell, J. R. Cady, and others, OSRD 4359, Progress Report 
M-411, Battelle Memorial Institute, Nov. 13, 1944. 

Div. 18-802.12-M17 

460. Examination of Enemy Alateriel. Metallurgical Examination of 

German Alechanical and Electrical Aircraft Tachometers, L. R. 
Jackson, W. W. Beaver, and H. W. Gillett, OSRD 4360, 
Progress Report M-412, Battelle Memorial Institute, 
Nov. 13, 1944. Div. 18-801.12-M7 

461. Examination of Enemy Materiel. Metallurgical Examination of 
the Instrument Panel of a Jumo 211 -B Direct Gasoline Injection 
Engine from a Junkers-88 German Bomber, L. R. Jackson, 
W. W. Beaver, and H. W. Gillett, OSRD 4364, Progress 
Report M-415, Battelle Memorial Institute, Nov. 13, 1944. 

Div. 18-801. 12-M6 

462. Examination of Enemy Materiel. Japanese Drift Meter or Bomb 

Sight, L. H. Grenell, J. R. Cady, and others, OSRD 4365, 
Progress Report M-416, Battelle Memorial Institute, Nov. 
13, 1944. Div. 1 8-802. 13-M3 

463. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Army 47 mm H. E. Projectiles, L. H. Grenell, J. R. 
Cady, and others, OSRD 4366, Progress Report M-417, 
Battelle Memorial Institute, Nov. 25, 1944. 

Div. 18-802.21-M22 

464. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Propeller Blades, L. H. Grenell, J. R. Cady, and 
others, OSRD 4367, Progress Report M-418, Battelle 
Memorial Institute, Nov. 25, 1944. Div. 1 8-802. 15-M3 

465. Examination of Enemy Materiel. Metallurgical Examination of 

Three Japanese Aircraft Landing Hooks Grenell, J. R. Cady, 

and others, OSRD 4388, Progress Report M-419, Battelle 
Memorial Institute, Nov. 25, 1944. Div. 18-802.1 1-M8 

466. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese Kinsei- 43 Aircraft Engine, L. H. Grenell, J. R. Cady, 
and H. W. Gillett, OSRD 4420, Progress Report M-422, 
Battelle Memorial Institute, Dec. 4, 1944. 

Div. 18-802.12-M18 

467. Examination of Enemy Materiel. Metallurgical Examination of 

a Gyro Compass from a Japanese Aircraft “R/IL,” Mark I, 
L. R. Jackson, W. W. Beaver, and H. W. Gillett, OSRD 
4421, Progress Report M-425, Battelle Memorial Institute, 
Dec. 4, 1944. Div. 1 8-802. 13-M5 

468. Examination of Enemy Materiel. Metallurgical Examination of a 
German Aircraft Fuel Consumption Meter and a Blinker-Type 
Oxygen Flow-Meter, L. R. Jackson, W. W. Beaver, and 
H. W. Gillett, OSRD 4422, Progress Report M-426, 
Battelle Memorial Institute, Dec. 4, 1 944. Div. 1 8-802.1 3-M4 

469. Examination of Enemy Materiel. Metallurgical Examination of 
a Japanese Bomb Hoist and Release, L. H. Grenell, J. R. Cady, 
and others, OSRD 4423, Progress Report M-428, Battelle 
Memorial Institute, Dec. 6, 1944. Div. 1 8-802.1 5-M4 


470. Examination of Enemy Materiel. Metallurgical Examination of 
Airframe Sections from Japanese Aircraft, L. H. Grenell, J. R. 
Cady, and others, OSRD 4429, Progress Report M-429, 
Battelle Memorial Institute, Dec. 6, 1944. 

Div. 18-802.11-M9 

471. Examination of Enemy Materiel. Aletallurgical Examination of 

Oleo Landing Strut and Wheel from Japanese ^^Sally” Mark II, 
L. H. Grenell, J. R. Cady, and others, OSRD 4424, 
Progress Report M-430, Battelle Memorial Institute, 
Dec. 6, 1944. Div. 18-802.1 1-MlO 

472. Examination of Enemy Materiel. Metallurgical Investigation of 
German 170 mm Gun Tubes, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 4463, Progress Report 
M-433, Battelle Memorial Institute, Dec. 12, 1944. 

Div. 18-801. 23-M14 

473. Examination of Enemy Materiel. Metallurgical Examination of 
Two Japanese Mechanical Impact Fuzes and Containers, L. H. 
Grenell, J. R. Cady, and others, OSRD 4454, Progress 
Report M-436, Battelle Memorial Institute, Dec. 8, 1944. 

Div. 18-802.21-M23 

474. Examination of Enemy Materiel. Metallurgical Examination of 
Parts from a Japanese Mamoru-11 Aircraft Engine, L. H. Gren- 
ell, J. R. Cady, and H. W. Gillett, OSRD 4455, Progress 
Report M-437, Battelle Memorial Institute, Dec. 8, 1944. 

Div. 18-802.12-M19 

475. Examination of Enemy Materiel. Metallurgical Investigation of 
German 150 mm. Gun Tube, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 4464, Progress Report 
M-438, Battelle Memorial Institute, Dec. 12, 1944. 

Div. 18-801.23-M15 

476. Examination of Enemy Materiel. Metallurgical Examination of 
Tail Wheel Assembly and Landing Gear Hydraulic Retracting 
Strut from a Japanese Aircraft ^^Dinahj’’ L. H. Grenell, J. R. 
Cady, and others, OSRD 4465, Progress Report M-441, 
Battelle Memorial Institute,Dec.8, 1 944.Div. 1 8-802. 1 1 -Ml 1 

477. Examination of Enemy Materiel. Metallurgical Examination of a 
German 7.92 mm MG-17 Aircraft Machine Gun, L. H. Grenell, 
J. R. Cady, and others, OSRD 4507, Progress Report 
M-443, Battelle Memorial Institute, Dec. 19, 1944. 

Div. 18-801.23-M16 

478. Examination of Enemy Materiel. Metallurgical Examination of 
an H.E. 15 cm Japanese Naval Projectile, L. H. Grenell, J. R. 
Cady, and others, OSRD 4548, Progress Report M-448, 
Battelle Memorial Institute, Jan. 5, 1945. 

Div. 18-802.21-M24 

479. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese 75 mm AA Ammunition, L. H. Grenell, J. R. Cady, 
and others, OSRD 4563, Progress Report M-449, Battelle 
Memorial Institute, Jan. 8, 1945. Div. 18-802. 21-M25 

480. Examination of Enemy Materiel. Metallurgical Examination of 
Two Welded Aluminum Sections from a German Mine. L. H. 
Grenell, J. R. Cady, and others, OSRD 4549, Progress 
Report M-453, Battelle Memorial Institute, Jan. 5, 1945. 

Div. 1 8-801. 3-M4 

481. Examination of Enemy Materiel. Metallurgical Examination of a 
Type 91, Change 3, 18-Inch Japanese Torpedo, L. H. Grenell, 
J. R. Cady, and others, OSRD 4593, Progress Report 
M-457, Battelle Memorial Institute and Mellon Institute 
of Industrial Research, Jan. 18, 1945. Div. 1 8-802. 24-M2 

482. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Aircraft Armor Plate, L. H. Grenell, J. R. Cady, 
and others, OSRD 4597, Progress Report M-464, Battelle 
Memorial Institute, Jan. 20, 1945. Div. 18-802. 11-M12 

483. Examination of Enemy Materiel. Metallurgical Investigation of 
German 50 mm Gun Tubes, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 4695, Progress Report 
M-473, Battelle Memorial Institute, Feb. 12, 1945. 

Div. 18-801.23-M17 


CONFIDENTIAL 


148 


BIBLIOGRAPHY 


484. Examination oj Enemy Materiel. Metallurgical Examination of 
Japanese 37 mm A. P., H.E. Ammunition, L. H. Grenell, J. R. 
Cady, and others, OSRD 4696, Progress Report M-474, 
Battelle Memorial Institute, Feb. 12, 1945. 

Div. 18-802.21-M26 

485. Examination of Enemy Materiel. Metallurgical Examination of 

the Hardware from Japanese and German Parachute Harnesses, 
L. H. Grenell, J. R. Cady, and others, OSRD 4697, 
Progress Report M-475, Battelle Memorial Institute, Feb. 
12, 1945. Div. 18-801. 13-M3 

486. Examination of Enemy Mathiel. Metallurgical Examination of 
Armor Plate from Japanese Aircraft ^^Betty,’^ L. H. Grenell, 
J. R. Cady, and others, OSRD 4776, Progress Report 
M-483, Battelle Memorial Institute, Mar. 3, 1945. 

Div. 18-802.11-M13 

487. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Electrical Cable, L. H. Grenell, J. R. Cady, and 
others, OSRD 4777, Progress Report M-485, Battelle 
Memorial Institute, Mar. 3, 1945. Div. 1 8-802. 3-M4 

488. Examination of Enemy Materiel. Metallurgical Examination of 
Captured Japanese Aluminum Pressure Vessels Used for the 
Storage of Oxygen, H. L. Anthony, OSRD 4812, Progress 
Report M-486, Battelle Memorial Institute, Mar. 5, 1945. 

Div. 18-802.3-M5 

489. Examination of Enemy Materiel. Metallurgical Examination of 
Two Japanese Kasei Engines, Models 77 and 15, L. H. Grenell, 
J. R. Cady, and H. W. Gillett, OSRD 4826, Progress Re- 
port M-488, Battelle Memorial Institute, Mar. 12, 1945. 

Div. 18-802.12-M20 

490. Examination of Enemy Materiel. Metallurgical Examination of 
a Japanese Model 92 Machine Gun, L. H. Grenell, J. R. Cady, 
and others, OSRD 4827, Progress Report M-489, Battelle 
Memorial Institute, Mar. 12, 1945. Div. 1 8-802. 23-MlO 

491. Metallurgical Examination of Enemy Materiel. Metallurgical In- 
vestigation of German 75 mm Gun Tubes, E. L. Bartholomew, 
Jr., M. S. Burton, and F. R. Evans, OSRD 4913, Progress 
Report M-498, Battelle Memorial Institute, Apr. 4, 1945. 

Div. 18-801.23-M18 

492. Examination of Enemy Materiel. Metallurgical Examination of 
Armor Plate from Japanese Aircraft ^Mily 2,” L. H. Grenell, 
J. R. Cady, and others, OSRD 4914, Progress Report 
M-501, Battelle Memorial Institute, Apr. 6, 1945. 

Div. 18-802.11-M14 

493. Examination of Enemy Matkiel. Metallurgical Examination of 
German MP-dSI/l 7.92 mm Machine Pistol, L. H. Grenell, 
J. R. Cady, and others, OSRD 4915, Progress Report 
M-502, Battelle Memorial Institute, Apr. 6, 1945. 

Div. 18-801. 23-M19 

494. Examination of Enemy Materiel. Metallurgical Examination of 
German Tank Track Links and Pins, L. H. Grenell, J. R. 
Cady, and others, OSRD 4916, Progress Report M-503, 
Battelle Memorial Institute, Apr. 6, 1 945. Div. 1 8-801 .24-M2 

495. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese Sakae-12 Engine No. 124676, L. H. Grenell, J. R. 
Cady, and H. W. Gillett, OSRD 4982, Progress Report 
M-504, Battelle Memorial Institute, Apr. 17, 1945. 

Div. 18-802.12-M21 

496. Examination of Enemy Materiel. Metallurgical Examination of 

Japanese 30 mm H.E. Incendiary and H.E. Tracer Ammunition, 
L. H. Grenell, J. R. Cady, and others, OSRD 4917, 
Progress Report M-506, Battelle Memorial Institute, Apr. 
6, 1945. Div. 18-802.21-M27 

497. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese Model 89 7.7 mm Aircraft Machine Gun, L. H. 
Grenell, J. R. Cady, and others, OSRD 5005, Progress 
Report M-508, Battelle Memorial Institute, Apr. 24, 1945. 

Div. 18-802.23-Mll 


498. Examination of Enemy Materiel. Metallurgical Examination of 
Landing Wheel and Strut, and Wing Sections, and Components 
from Japanese Aircraft, Frances,''^ A. deS. Brasunas andD. O. 
Leeser, OSRD 5020, Progress Report M-513, Battelle 
Memorial Institute, May 1, 1945. Div. 18-802.1 1-Ml 5 

499. Examination of Enemy Mathiel. Metallurgical Examination of 

Two Japanese Gasoline Tanks from a '''‘Judy'’’ Type Aircraft 
Wing, C. E. Heussner, J. G. Dunleavy, and H. W. Gillett, 
OSRD 5021, Progress Report M-514, Battelle Memorial 
Institute, May 1, 1945. Div. 1 8-802. 14-M5 

500. Examination of Enemy Materiel. Metallurgical Examination of a 

German 7.62 cm. A.P.wj Tungsten Carbide Short Case (Russian) 
Shot, L. H. Grenell, J. R. Cady, and others, OSRD 5048, 
Progress Report M-517, Battelle Memorial Institute, May 
11, 1945. Div. 18-801.21-M25 

501. Examination of Enemy Mathiel. Metallurgical Examination of a 
German 88 mm A.P., H.E., C.B.C. Pak 43 Shell, L. H. Grenell, 
J. R. Cady, and others. OSRD 5049, Progress Report 
M-518, Battelle Memorial Institute, May 11, 1945. 

Div. 18-801.21-M26 

502. Examination of Enemy Mathiel. Metallurgical Examination of a 
Japanese 57 mm Tank Gun, Model 97, L. H. Grenell, J. R. 
Cady, and others, OSRD 5104, Progress Report M-521, Bat- 
telle Memorial Institute, May 21,1945. Div. 18-802. 23-M12 

503. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese Aircraft ^Hrving’^ Airframe, L. H. Grenell, C. E. 
Heussner, and others, OSRD 5107, Progress Report M- 

522, Battelle Memorial Institute, May 21, 1945. 

Div. 18-802.11-M16 

504. Examination of Enemy Mathiel. Metallurgical Examination of 
Armor Plate from Japanese Aircraft Frank, L. H. Grenell, 
J. R. Cady, and others, OSRD 5108, Progress Report M- 

523, Battelle Memorial Institute, May 21, 1945. 

Div. 18-802.1 1-Ml 7 

505. Examination of Enemy Mathiel. Metallurgical Examination of 
a Japanese Kinsei-43 Aircraft Engine, L. H. Grenell, J. R. 
Cady, and H. W. Gillett, OSRD 5109, Progress Report 
M-524, Battelle Memorial Institute, May 22, 1945. 

Div. 1 8-802. 12-M22 

506. Examination of Enemy Mathiel. Metallurgical Investigation of 
German 88 mm Guns, E. L. Bartholomew, Jr., M. S. Burton, 
and F. R. Evans, OSRD 5110, Progress Report M-525, Bat- 
telle Memorial Institute, May 22, 1 945. Div. 1 8-801 .23-M20 

507. Examination of Enemy Mathiel. Metallurgical Examination of 
German Tank Armor Plate, L. H. Grenell, J. R. Cady, and 
others, OSRD 5133, Progress Report M-532, Battelle 
Memorial Institute, May 29, 1945. Div. 1 8-801. 22-M3 

508. Examination of Enemy Mathiel. Metallurgical Examination of 

Two Japanese Oerlikon-Type 20 mm Aircraft Machine Guns for 
1944, L. H. Grenell, J. R. Cady, and others, OSRD 5134, 
Progress Report M-533, Battelle Memorial Institute, 
May 29, 1945. Div. 18-802.23-M13 

509. Examination of Enemy Mathiel. Metallurgical Examination of 
5-inch Japanese Naval Projectile, L. H. Grenell, J. R. Cady, 
and others, OSRD 5135, Progress Report M-534, Battelle 
Memorial Institute, May 29, 1945. Div. 1 8-802. 21-M28 

510. Examination of Enemy Mathiel. Metallurgical Examination of 

German 75 mm Kw.K 42, AP-HE-C & BC Projectile and 
Cartridge Case, L. H. Grenell, J. R. Cady, and others, 
OSRD 5136, Progress Report M-535, Battelle Memorial 
Institute, May 28, 1945. Div. 1 8-801. 21-M27 

511. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese Homare-11 Aircraft Engine No. 11515, L. H. Grenell, 
J. R. Cady, and H. W. Gillett, OSRD 5199, Progress Re- 
port M-538, Battelle Memorial Institute, June 13, 1945. 

Div. 1 8-802. 12-M23 


CONFIDENTIAL 


BIBLIOGRAPHY 


149 


512. Examination of Enemy Materiel. Metallurgical Examination of 
German and Japanese Bushings and Oil Lines, L. H. Grcncll, 
J. R. Cady, and others, OSRD 5200, Progress Report 
M-539, Battelle Memorial Institute, June 12, 1945. 

‘ Div. 18-801. 11-Ml 

513. Examination of Enemy Materiel. APetallurgical Examination of 
Japanese 47 mm Antitank Gun, L. H. Grenell, J. R. Cady, 
and others, OSRD 5227, Progress Report M-543, Battelle 
Memorial Institute, June 19, 1945. Div. 18-802. 23-M14 

514. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese Aircraft 20 mm Browning-Type^^ Machine Gun, 

L. H. Grenell, J. R. Cady, and others, OSRD 5228, 

Progress Report M-544, Battelle Memorial Institute, June 
19, 1945. Div. 18-802.23-M15 

515. Examination of Enemy Materiel. Metallurgical Examination of 

Small Arms Barrels, L. H. Grenell, J. R. Cady, and others, 
OSRD 5229, Progress Report M-545, Battelle Memorial 
Institute, June 19, 1945. Div. 1 8-801. 23-M21 

516. Examination of Enemy Materiel. Metallurgical Examination of 

a German Canteen and Alesskit; and Japanese Canteens and 
Helmets, L. H. Grenell, J. R. Cady, and others, OSRD 
5265, Progress Report M-546, Battelle Memorial Insti- 
tute, June 22, 1945. Div. 18-801. 3-M5 

517. Examination of Enemy Materiel. Aletallurgical Examination of 
Tungsten Carbide Powder and Compacts, L. H. Grenell, J. R. 
Cady, and others, OSRD 5230, Progress Report M-547, 
Battelle Memorial Institute,June 21 , 1 945. Div. 1 8-803. 2-M4 

518. Examination of Enemy Aiathiel. Aietallurgical Investigation of an 

8 cm. Japanese Antiaircraft Gun No. 2404 {FMAR-203), E. L. 
Bartholomew, Jr., M. S. Burton, and F. R. Evans, OSRD 
5323, Progress Report M-552, Battelle Memorial Insti- 
tute, Feb. 9, 1945. Div. 18-802.23-M16 

519. Examination of Enemy Materiel. Metallurgical Examination of 

Tire and Tube from Japanese Plane Frances, OSRD 5331, 
Progress Report M-554, Battelle Memorial Institute, July 
11,1945. Div. 18-802.11-M18 

520. Examination of Enemy Materiel. Aietallurgical Examination of 
Japanese 37 -mm Tank Gun No. 842, E. L. Bartholomew, Jr., 

M. S. Burton, and F. R. Evans, OSRD 5357, Progress 
Report M-559, Battelle Memorial Institute, July 24, 1945. 

Div. 18-802.23-M17 

521. Examination of Enemy Materiel. Metallurgical Examination of 
Flap Tracks from ^^Judy" and Frances’’'’ and Skin Sections from 

Frank,"’’’ C. E. Heussner, D. O. Leeser, and H. W. Gillett, 
OSRD 5374, Progress Report M-560, Battelle Memorial 
Institute, July 24, 1945. Div. 18-802.1 1-M19 

522. Examination of Enemy Mathiel. Metallurgical Examination of a 

Japanese 50-mm Mortar Grenade Smoke Shell and Fuze, L. H. 
Grenell, A. B. Westerman, and others, OSRD 5409, 
Progress Report M-565, Battelle Memorial Institute, 
Aug. 3, 1945. Div. 18-802.21-M29 

523. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese 20 mm Aircraft Machine Gun, L. H. Grenell, A. B. 
Westerman, and others, OSRD 5410, Progress Report 
M-567, Battelle Memorial Institute, Aug. 3, 1945. 

Div. 18-802.23-M18 

524. Examination of Enemy Materiel. Metallurgical Examination of 
Float Strut from Japanese Aircraft ‘‘'‘PaulJ L. H. Grenell, 
A. B. Westerman, and others, OSRD 5411, Progress Re- 
port M-568, Battelle Memorial Institute, Aug. 3, 1945. 

Div. 1 8-802. 11-M20 

525. Examination of Enemy Mathiel. Metallurgical Examination of 
a Japanese Kawasaki Type 2 Aircraft Engine, L. H. Grenell, 
J. R. Cady, and H. W. Gillett, OSRD 5472, Progress Re- 
port M-570, Battelle Memorial Institute, Aug. 15, 1945. 

Div. 1 8-802. 12-M25 


526. Examination of Enemy Alateriel. Metallurgical Examination of 
German Volkswagen Engine, L. H. Grenell, A. B. Westerman, 
and H. W. Gillett, OSRD 5456, Progress Report M-571, 
Battelle Memorial Institute, Aug. 15, 1945. 

Div. 18-801. 3-M6 

527. Examination of Enemy Alateriel. Metallurgical Examination of 
A.P. and H.E. Ammunition for Japanese 20 mm Browning-Type 
Gun, L. H. Grenell, A. B. Westerman, and others, OSRD 

5478, Progress Report M-574, Battelle Memorial Insti- 
tute, Aug. 23, 1945. Div. 18-802.21-M31 

528. Examination of Enemy Materiel. Aietallurgical Examination of 
German Crash-Flak Helmet and Japanese Horseshoes and Shoe 
Last, L. H. Grenell, A. B. Westerman, and others, OSRD 

5479, Progress Report M-575, Battelle Memorial Insti- 
tute, Aug. 23, 1945. Div. 18-801. 3-M7 

529. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese 40 mm A.P. H.E. Shell, L. H. Grenell, A. B. Wester- 
man, and others, OSRD 5480, Progress Report M-576, 
Battelle Memorial Institute, Aug. 23, 1945. 

Div. 18-802.21-M30 

530. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese 7.92 mm Type 1 Flexible A/C Machine Gun {Twin 
Barreled) Hand-Operated Turret 12.7 mm Machine Gun, Sally 
and Lily Dorsal Position, L. H. Grenell, W. W. Beaver, and 
H. W. Gillett, OSRD 5493, Progress Report M-577, 
Battelle Memorial Institute, Aug. 27, 1945. 

Div. 18-802.23-M19 

531. Examination of Enemy Mathiel. Aietallurgical Examination of 
a German Panther {Mark V) Tank Engine, L. H. Grenell, 
A. B. Westerman, and others, OSRD 5504, Progress Re- 
port M-580, Battelle Memorial Institute, Aug. 27, 1945. 

Div. 1 8-801. 24-M3 

532. Examination of Enemy Materiel. Metallurgical Examination of a 

Japanese 7.92 mm Type 98 Flexible A/C Machine Gun, L. H. 
Grenell, A. B. Westerman, and others, OSRD 5516, Prog- 
ress Report M-581, Battelle Memorial Institute, Aug. 31, 
1945. Div. 18-802.23-M20 

533. Examination of Enemy Mathiel. Metallurgical Examination of 

Wing Hinge Fittings from Japanese ^^Frances’’^ Aircraft, L. H. 
Grenell, A. B. Westerman, and H. W. Gillett, OSRD 
5517, Progress Report M-582, Battelle Memorial Insti- 
tute, Aug. 31, 1945. Div. 18-802.11-M21 

534. Examination of Enemy Mathiel. Metallurgical Examination of 
a Japanese Droppable Fuel Tank, L. H. Grenell, A. B. Wester- 
man, and others, OSRD 5518, Progress Report M-583, Bat- 
telle Memorial Institute, Aug. 31, 1945. Div. 18-802. 14-M6 

535. Examination of Enemy Mathiel. Metallurgical Examination of a 
Japanese 57 mm A.P. -H.E. andH.E. Ammunition, L.H. Grenell, 
A. B. Westerman, and others, OSRD 5519, Progress 
Report M-584, Battelle Memorial Institute, Aug. 31, 1945. 

Div. 18-802.21-M32 

536. Examination of Enemy Mathiel. Metallurgical Investigation of 
a Japanese 75 mm Regimental Gun, E. L. Bartholomew, Jr., 
M. S. Burton, and F. R. Evans, OSRD 5693, Progress 
Report M-585, Battelle Memorial Institute, Sept. 14, 1945. 

Div. 18-802.23-M21 

537. Examination of Enemy Mathiel. Examination of German Oxygen 

Valve and German and Japanese Oxygen Valve Seats, L. H. 
Grenell, A. B. Westerman, and others, OSRD 5726, 
Progress Report M-589, Battelle Memorial Institute, Sept. 
19, 1945. Div. 18-801. 13-M4 

538. Examination of Enemy Mathiel. Metallurgical Examination of 
German '•'■Panther’’’’ {Mark V) Tank Parts, L. H. Grenell, 
A. B. Westerman, and others, OSRD 5712, Progress Re- 
port M-590, Battelle Memorial Institute, Sept. 19, 1945. 


CONFIDENTIAL 


150 


BIBLIOGRAPHY 


Div. 1 8-801. 24-M4 

539. Examination of Enemy Materiel. Metallurgical Examination of 
German 75 mm Pak 40 Antitank Gun Carriage, L. H. Grenell, 
A. B. Westerman, and others, OSRD 5678, Progress Re- 
port M-592, Battelle Memorial Institute, Sept. 14, 1945. 

Div. 1 8-801. 23-M22 

540. Examination oj Enemy Materiel. Metallurgical Examination of 

Japanese 75 mm Anti-Aircraft H. E. Shell with Euge, L. H. 
Grenell, A. B. Westerman, and others, OSRD 5725, 
Progress Report M-593, Battelle Memorial Institute, 
Sept. 19, 1945. Div. 18-802.21-M36 

541. Examination of Enemy Materiel. Metallurgical Examination of 
Japanese 105 mm H. E. Projectile, L. H. Grenell, A. B, 
Westerman, and others, OSRD 5713, Progress Report 
M-594, Battelle Memorial Institute, Sept. 19, 1945. 

Div. 18-802.21-M33 

542. Examination of Enemy Materiel. Metallurgical Examination of 

Japanese 47 mm C/R H. E. UfF Shell for Model 1 AfT Gun, 
L. H. Grenell, A. B. Westerman, and others, OSRD 5714, 
Progress Report M-595, Battelle Memorial Institute, 
Sept. 19, 1945. Div. 18-802.21-M34 

543. Examination of Enemy Materiel. Metallurgical Examination of a 

Japanese Cj R 20 mm Hotchkiss H. E. Shell for Model 98 A. A. 
Gun, L. H. Grenell, A. B. Westerman, and others, OSRD 
5715, Progress Report M-596, Battelle Memorial Institute, 
Sept. 19, 1945. Div. 18-802.21-M35 

544. Examination of Enemy Mathiel. Metallurgical Examination of 
Japanese Kasei-21 Aircraft Engine No. 2189, L. H. Grenell, 
A. B. Westerman, and others, OSRD 6008, Progress Re- 
port M-597, Battelle Memorial Institute, Oct. 1, 1945. 

Div. 18-802.12-M26 

545. Examination of Enemy Materiel. Metallurgical Examination of a 

Japanese Magnetic Antitank Mine and Fuze, J. G. Dunleavy, 
H. W. Gillett, and W. E. McKibben, OSRD 5677, Prog- 
ress Report M-598, Battelle Memorial Institute, Sept. 14, 
1945. ‘ Div. 18-802.24-M3 

546. Examination of Enemy Materiel. Metallurgical Examination of a 
Japanese 20 cm Rocket, L. H. Grenell, A. B. Westerman, 
and H. W. Gillett, OSRD 57 1 6, Progress Report M-599, Bat- 
telle Memorial Institute, Sept. 19, 1945. Div. 1 8-802. 24-M4 

547. Examination of Enemy Materiel. Metallurgical Examination of a 
German Aircraft Torpedo and Warhead, L. H. Grenell, A. B. 
Westerman, and others, OSRD 5717, Progress Report 
M-600, Battelle Memorial Institute, Sept. 19, 1945. 

Div. 18-801. 3-M8 

548. Examination of Enemy Mathiel. Metallurgical Investigation of 
Japanese 81 mm Mortars, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 6009, Progress Report 
M-601, Battelle Memorial Institute, Sept. 28, 1945. 

Div. 18-802.23-M22 

549. Examination of Enemy Materiel. Metallurgical Investigation of 
a Japanese 15 cm Howitzer, E. L. Bartholomew, Jr., M. S. 
Burton, and F. R. Evans, OSRD 6010, Progress Report 
M-602, Battelle Memorial Institute, Sept. 28, 1945. 

Div. 18-802.23-M23 

550. Examination of Enemy Matkiel. Metallurgical Examination of a 
German M.G. Anti-Aircraft Tripod, L. H. Grenell, A. B. 
Westerman, and others, OSRD 5727, Progress Report 
M-603, Battelle Memorial Institute, Sept. 19, 1945. 

Div. 18-801.23-M23 

551. “A Sample Cylinder Head from a Japanese Homare-21 

Aircraft Engine,” L. H. Grenell, letter to Lt. Comdr. 
A. J. M. Hamon, Battelle Memorial Institute, July 17, 
1945. Div. 1 8-802. 12-M24 

552. “The German Carburetor Air Cleaner on a DB-601 En- 

gine Messerschmitt 109 Airplane,” L. H. Grenell, letter to 
Lt. Col. J. M. Hayward, Battelle Memorial Institute, 
Aug. 13, 1945. Div. 18-801. 11-M2 


553. “The Section of German 80 mm Mortar Shell,” H. W. 

Gillett, letter to Lt. Col. C. H. Greenall, Battelle Mem- 
orial Institute, Feb. 22, 1945. Div. 1 8-801. 21-M24 

554. Examination of Enemy Materiel, L. H. Grenell, A. B. Wester- 
man, and H. W. Gillett, OSRD 6171, Final Report M-604, 
Battelle Memorial Institute, Oct. 19, 1945. Div. 18-800-Ml 

555. Enemy Materiel from the Metallurgical Point of View, J. R. 
Cady, H. W. Gillett, and L. H. Grenell, Report 666, 
Battelle Memorial Institute, February 1945, pp. 289-320. 

Div. 18-803.2-M3 

556. “Metallurgy of Foreign Automotive Materiel,” Col. J. H. 
Frye, S.A.E. Journal (Transactions), Vol. 53, No. 8, August 
1945, pp. 450-479. 

557. Abstract of Confidential Report on Nickel in Japan, H. W. Gil- 

lett, OSRD 760, Advisory Report M-13, National Acad- 
emy of Sciences, Aug. 1, 1942. Div. 1 8-802. 3-Ml 

558. Development of a Suitable and Non-Critical Fused Inorganic 
Coating for Cooking Utensils and Other Quartermasters Items, 

G. H. McIntyre and E. E. Bryant, OSRD 3166, Final 
Report M-193, Ferro Enamel Corp., Jan. 13, 1944. 

Div. 18-901. 11-Ml 

559. Silver Plating of Steel Flatware, C. L. Faust and Hiram S. 
Lukens, OSRD 1240, Advisory Report M-51, National 
Academy of Sciences, Mar. 1, 1943. Div. 18-901.12-M2 

560. Flatware for Army Use, Part I, Hiram S. Lukens, OSRD 

5141, Final Report M-51 5, National Research Council, 
May 29, 1945. Div. 1 8-901. 12-M2 

561. Flatware for Army Use, Part H, Hiram S. Lukens, OSRD 

6568, Final Report M-632, National Academy of Sciences, 
Jan. 23, 1946. Div. 1 8-901. 12-M3 

562. Metallurgical Studies and Surveys of Army Quartermaster Corps 
Supplies: Part I — Problems Under Investigation for the Office 
of the Quartermaster General for the Period February 1, 1943 to 
August 1, 1943; Part 1 1 — Camouflage of Mess Gear, R. S. 
Williams, OSRD 2065, Final Report M-166, Massa- 
chusetts Institute of Technology, Nov. 16, 1943. 

Div. 18-901. 2-Ml 

563. Development and Evaulation of an Economical Corrosion Resisting 

Alloy for Quartermaster Items, H. A. Pray and F. W. Fink, 
OSRD 4673, Final Report M-469, Battelle Memorial In- 
stitute, Feb. 5, 1945. Div. 1 8-901. 2-M2 

564. Literature Survey on the Low-Temperature Properties of Metals, 
A. E. White and C. A, Siebert, OSRD 281, Report B-122, 
Vol. 1-7, University of Michigan, Dec. 9, 1941. 

Div. 18-902.3-Ml 

565. On the Propagation of Plastic Deformation in Solids, Theodore 
von Karman, OSRD 365, Progress Report A-29, Cali- 
fornia Institute of Technology, Jan. 30, 1942. 

Div. 18-902.1 1-Ml 

566. Preliminary Experiments on the Propagation of Plastic Deforma- 
tion, Pol E. Duwez, OSRD 3207, Division 2, Report A-244, 
California Institute of Technology, Feb. 2, 1944. 

Div. 18-902.1 1-M5 

567. Propagation of Plastic Strain in Tension, Pol E. Duwez, 

D. S. Wood, and Donald S. Clark, OSRD 931, Progress 
Report A-99, California Institute of Technology, Oct. 5. 
1942. Div. 18-902.11 -M2 

568. Propagation of Plastic Waves in Tension Specimens of Finite 

Length. Theory and Methods of Integration, Theodore von 
Karman, H. F. Bohnenblust, and D. H. Hyers, OSRD 946, 
Progress Report A-103, California Institute of Technology, 
Oct. 15, 1942. Div. 1 8-902. 11-M3 

569. Graphical Solutions for Problems of Strain Propagation in Tension, 

H. F. Bohnenblust, J. V. Charyk, and D. H. Hyers, OSRD 

1204, Progress Report A-131, California Institute of Tech- 
nology, Jan. 21, 1943. Div. 18-902.11-M4 


CONFIDENTIAL 


BIBLIOGRAPHY 


151 


570. Behavior of Metals Under Dynamic Conditions. Progression of 
Yielding, Pol E, Duwez, H. E. Martens, and Donald S. 
Clark, OSRD 4453, Progress Report M-409, California 
Institute of Technology, Dec. 9, 1 944. Di v. 1 8-902. 1 1 -M8 

571. Behavior of Metals Under Dynamic Conditions. The Propagation 
of Plastic Strain in Compression, Pol E. Duwez, Donald S. 
Clark, and H. E. Martens, OSRD 3886, Progress Report 
M-302, California Institute of Technology, July 7, 1944. 

Div. 18-902.1 1-M6 

572. Effect of Stopped Impact and Reflection on the Propagation of 
Plastic Strain in Tension, Pol E. Duwez, D. S. Wood, and 
others, OSRD 988, Division 2, Progress Report A- 108, 
California Institute of Technology, Nov. 4, 1942. 

Div. 1 8-902. 12-M2 

573. Factors Influencing the Propagation of Plastic Strain in Long 
Tension Specimens, Pol E. Duwez, D. S. Wood, and Donald 
S. Clark, OSRD 1304, Progress Report A-159, California 
Institute of Technology, Mar. 16, 1943. Div. 1 8-902. 12-M4 

574. Influence of Specimen Length on Strain Propagation in Tension, 

Pol E. Duwez, D. S. Wood, and Donald S. Clark, OSRD 
957, Progress Report A-105, California Institute of Tech- 
nology, Oct. 22, 1942. Div. 1 8-902. 12-Ml 

575. The Influence of Specimen Dimensions and Shape on the Results 
of Tensile Impact Tests, D. S. Wood, Pol E. Duwez, and 
Donald S. Clark, OSRD 3028, Division 2, Report A-237, 
California Institute of Technology, Dec. 16, 1943. 

Div. 1 8-902. 12-M8 

576. Discussion of Energy Measurements in Tension Impact Tests at 
the California Institute of Technology, Pol E. Duwez, Donald 
S. Clark, and D. S. Wood, OSRD 1829, Division 2, Report 
A-217, California Institute of Technology, Sept. 15, 1943. 

Div. 1 8-902. 12-M7 

577. The Influence of Impact Velocity on the Tensile Properties of Plain 

Carbon Steels and of a Cast-Steel Armor Plate, Pol E. Duwez, 
Donald S. Clark, and D. S. Wood, OSRD 1274, Division 
2, Report A-154, California Institute of Technology, Mar. 
2, 1943. Div. 1 8-902. 12-M3 

578. Dynamic Tests of the Tensile Properties of SAE 1020 Steels, 
ARMCO Iron and 17S-T Aluminum Alloy, Pol E. Duwez, 

D. S. Wood, and Donald S. Clark, OSRD 1490, Division 

2, Report A-182, California Institute of Technology, May 
13, 1943. Div. 18-902.12-M5 

579. The Influence of Impact Velocity on the Tensile Properties of Class 
B Armor Plate, Heat-Treated Alloy Steels and Stainless Steel, Pol, 

E. Duwez, D. S.Wood, and Donald S. Clark, OSRD 1641, 

Division 2, Report A-195, California Institute of Tech- 
nology, July 15 ,1943. Div. 18-902. 12-M6 

580. The Influence of Velocity on the Tensile Properties of a Carbon 

Steel, Two National Emergency Steels, and a Manganese Steel, 
Donald S. Clark, Pol E. Duwez, and D. S. Wood, OSRD 
3180, Division 2, Report A-241, California Institute of 
Technology, Jan. 22, 1944. Div. 1 8-902. 12-M9 

581. The Influence of Impact Velocity on the Tensile Properties of Four 

Magnesium Alloys and 24S Aluminum Alloy, Donald S. Clark, 
Pol E. Duwez, and D. S. Wood, OSRD 3256, Division 2, 
Report A-249, California Institute of Technology, Feb. 12 j 
1944. Div. 18-902.12-M10 

582. The Influence of Impact Velocity on the Tensile Properties of Three 

Types of Ship Plates: MS, HTS, STS, Donald S. Clark, 
Pol E. Duwez, and D. S. Wood, OSRD 3420, Division 2, 
Report A-261, California Institute of Technology, Mar. 23, 
1944. Div. 1 8-902. 12-Mll 

583. Behavior of Metals Under Dynamic Conditions. Influence of Im- 
pact Velocity on the Tensile Properties of NE-8715, NE-94415, 
SAE 1045 and SAE 1090 Steels, Donald S. Clark, Pol E. 
Duwez, and D. S. Wood, OSRD 3695, Progress Report 
M-257, California Institute of Technology, May 9, 1944. 

Div. 18-902.12-M13 


584. Behavior of Metals Under Dynamic Conditions. The Influence of 
Impact Velocity on the Tensile Properties of Three Gauges of Furni- 
ture Steel Sheets, Pol E. Duwez, Donald S. Clark, and H. E. 
Martens, OSRD 3696, Progress Report M-264, California 
Institute of Technology, May 9, 1944. Div. 18-902. 12-Ml 2 

585. Behavior of Metals Under Dynamic Conditions. The Influence of 

Impact Velocity on the Tensile Properties of Some Metals and 
Alloys, Donald S. Clark and Pol E. Duwez, OSRD 3837, 
Progress Report M-288, California Institute of Technology, 
June 19, 1944. Div. 18-902. 12-Ml 4 

586. Behavior of Metals Under Dynamic Conditions. The Influence of 
Hardness and Type of Heat Treatment on the Static and Impact 
Tensile Properties of an SAE 4340 Steel, Pol E. Duwez, 
H. E. Martens, and others, OSRD 4775, Progress Report 
M-462, California Institute of Technology, Feb. 19, 1945. 

Div. 18-902. 12-Ml 5 

587. Behavior of Metals Under Dynamic Conditions. A Preliminary 
Investigation of the Mechanism of Penetration from the Stand- 
point of Strain Propagation, Donald S. Clark and Pol E. 
Duwez, OSRD 3957, Progress Report M-317, California 
Institute of Technology, July 19, 1944. Div. 18-902.1 1-M7 

588. The Behavior of Long Means Under Impact Loading, Pol E. 
Duwez, Donald S. Clark, and others, OSRD 1828, Report 
A-216, California Institute of Technology, Sept. 13, 1943. 

Div. 18-902.13-M2 

589. Behavior of Metals Under Dynamic Conditions. Behavior of 

Clamped Beams Under Impact Loading, Pol E. Duwez, H. E. 
Martens, and Donald S. Clark, OSRD 4043, Progress 
Report M-338, California Institute of Technology, Aug. 
16, 1944. Div. 18-902.13-M6 

590. Deflection and Perforation of Steel Plates at Impact Velocities up 
to 150 Ft/ Sec., Pol E. Duwez, D. S. Wood, and Donald S. 
Clark, OSRD 1402, Preliminary Report A-175, California 
Institute of Technology, Apr. 23, 1943. Div. 18-902. 13-Ml 

591. The Static and Dynamic Plastic Bending of Plates, D. H. 

Hyers, OSRD 2018, Report A-228, California Institute of 
Technology, Nov. 16, 1943. Div. 1 8-902. 13-M3 

592. The Behavior of Large Plates Under Impact Loading, Pol E. 
Duwez, Donald S. Clark, and others, OSRD 3292, Report 
A-254, California Institute of Technology, Feb. 25, 1944. 

Div. 1 8-902. 13-M4 

593. Behavior of Metals Under Dynamic Conditions. Some Static and 
Dynamic Properties of ^amac II Die Cast Alloy in Relation to 
Its Use in Mark 140 {HIR3) Fuse, Donald S. Clark, Pol E. 
Duwez, and D. S. Wood, OSRD 3425, Progress Report 
M-234, California Institute of Technology, Mar. 27, 1944. 

Div. 1 8-902. 13-M5 

594. Behavior of Metals Under Dynamic Conditions. The Influence of 
Pure Strain Rate on Tensile Properties of Three Types of Ship 
Plate, Pol E. Duwez, H. E. Martens, and others, OSRD 

4773, Progress Report M-459, California Institute of 

Technology, Feb. 19, 1945. Div. 1 8-902. 15-M2 

595. Behavior of Metals Under Dynamic Conditions. The Application 

of Pure Strain Rate Tests to an Investigation of Two 76 mm 
Gun Tubes, Pol E. Duwez, H. E. Martens, and others, 
OSRD 4729, Progress Report M-460, California Institute 
of Technology, Feb. 19, 1945. Div. 18-902.15-Ml 

596. Behavior of Metals Under Dynamic Conditions. Preliminary Study 

of the Influence of Rapid Loading and Time at Load on the 
Initiation of Plastic Deformation in Tension, Pol E. Duwez, 
H. E. Martens, and Donald S. Clark, OSRD 4621, Prog- 
ress Report M-450, California Institute of Technology, 
Jan. 22, 1945. Div. 1 8-902. 14-Ml 

597. Behavior of Metals Under Dynamic Conditions. The Design of a 
Hydro- Pneumatic Machine for Rapid Load Tensile Testing, 
D. A. Elmer, Donald S. Clark, and D. H. Hyers, OSRD 

4774, Progress Report M-461, California Institute of 

Technology, Feb. 19, 1945. Div. 1 8-902. 14-M2 


CONFIDENTIAL 


152 


BIBLIOGRAPHY 


598. Behavior of Metals Under Dynamic Conditions, Donald S. 
Clark, OSRD 4868, Final Report M-492, California 
Institute of Technology, Mar. 27, 1945. Div. 18-902.1 -Ml 

599. Investigation of the Effects of Impurities on the Ferromagnetism of 

Non-Ferrous Alloys, Allison Butts and J. H. Frye, Jr., 
OSRD 3694, Progress Report M-279, Lehigh University, 
May 20, 1944. Div. 18-902.2-Ml 

600. Investigation of the Effect of Impurities on the Ferromagnetism of 

Non-Ferrous Alloys, Allison Butts, J. H. Frye, Jr., and P. L. 
Reiber, Jr., OSRD 4056, Progress Report M-335, Lehigh 
University, Aug. 24, 1944. Div. 1 8-902. 2-M2 

601. Investigation of the Effects of Impurities on the Ferromagnetism 

of Non-Ferrous Alloys, Allison Butts and P. L. Reiber, Jr., 
OSRD 4442, Progress Report 407, Lehigh University, 
Dec. 4, 1944. Div. 1 8-902. 2-M3 

602. Investigation of the Effects of Impurities on the Ferromagnetism of 

Non-Ferrous Alloys, Allison Butts and P. L. Reiber, Jr., 
OSRD 4833, Progress Report M-479, Lehigh University, 
Mar. 20, 1945. Div. 18-902.2-M4 

603. Investigation of the Effects of Impurities on the Ferromagnetism of 

Non-Ferrous Alloys, P. L. Reiber, Jr., and Allison Butts, 
OSRD 5471, Progress Report M-548, Lehigh University, 
Aug. 20, 1945. Div. 18-902.2-M5 


604. Industrial Applications of Chromium Plating, M. Kolodney 

OSRD 1074, Advisory Report M-26, National Academy 
of Sciences, Nov. 27, 1942. Div. 18-900-Ml 

605. Proposed Research Project: Rivets and Rivet Steels, OSRD 1162, 

Advisory Report M-42, National Academy of Sciences, Jan. 
22, 1943. Div. 18-900-M2 

606. Osmium, E. M. Wise, OSRD 1750, Advisory Report M-134, 
National Academy of Sciences, Aug. 27, 1943. 

Div. 18-902.4-Ml 

607. Possibilities of Interchangeable Use of the Materials and Alloys 
of the Platinum Group, Silver, Tungsten, and Others in Electrical 
Contacts, E. M. Wise, OSRD 5163, Advisory Report M- 
499, National Academy of Sciences, May 30, 1945. 

Div. 18-902.4-M2 

608. Upgrading of Lead-Bearing Copper Alloy Scrap, OSRD 1244, 

Advisory Report M-55, National Academy of Sciences, 
Mar. 5, 1943. Div. 18-900-M3 

609. Acceptance Tests for Plain Carbon Steel Gun Forgings and Other 

Ordnance Forgings, R. F. Mehl and A. H. Grobe, OSRD 
5018, Final Report M-466, Carnegie Institute of Tech- 
nology, May 3, 1945. Div. 18-301 -M3 


CONFIDENTIAL 


OSRD APPOINTEES 

DIVISION 18 

Chief 

Clyde Williams 


Technical Aides 

Louis Jordan S. L. Kruegel 

David C. Minton, Jr. 


Members 

H. W. Gillett Zay Jeffries 

S. D. Heron R. F. Mehl 


CONFIDENTIAL 


153 



154 


CONFIDENTIAL 





MEMBERS OF THE WAR METALLURGY COMMITTEE 


Chairman 

Clyde Williams, Director 
Battelle Memorial Institute 
Columbus, Ohio 


Vice Chairman 
Zay Jeffries, Vice President 
General Electric Company 
Pittsfield, Massachusetts 


Executive Secretary 
Louis Jordan 

War Metallurgy Committee 
Washington, D. C. 


Members 


Carl Breer, ^'ice President 
Chrysler Corporation 
Detroit, Michigan 
Lyman J. Briggs, Director 

National Bureau of Standards 
^Vashington, D. C. 

James H. Critchett, Vice President 

Union Caii:)ide &: Carbon Research Labs, 
New York, N. Y. 

Col. R. S. A. Dougherty, Manager 
Research and Development 
Bethlehem Steel Company 
Bethlehem, Pennsylvania 
Rudolph Fnrrer, Vice President 
A. O. Smith Corporation 
Milwaukee, ^Visconsin 
H. W. Gillett, Chief Technical Advisor 
Battelle Memorial Institute 
Columbus, Ohio 
S. D. Heron 

Ethyl Corporation 
Detroit, Michigan 
R. P. Heuer, Vice President 
General Refractories Company 
Philadelphia, Pennsylvania 
Col. G. F. Jenks ^ 

232 Avondale Avenue 
Los Angeles, California 
J. B. Johnson, Chief 

Materials Laboratory, Engineering Division 
Army Air Forces, Wright Field 
Dayton, Ohio 
John Johnston, Director 
Research Laboratory 
U. S. Steel Corporation 
Kearny, New Jersey 
Thomas L. Joseph 

Head, Department of Metallurgy 
University of Minnesota 
Minneapolis, Minnesota 
Vsevolod N, Krivobok 

International Nickel Co., Inc, 

New York, N. Y. 

Frederick Laist, Vice President 
Anaconda Copper Mining Co. 

New York, N. Y. 


^V. K. Lewis 

Head, Department of Chemical Engineering 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 
C. E. MacQuigg, Dean 
College of Engineering 
Ohio State University 
Columbus, Ohio 
C. L. McCuen, Vice President 
General Motors Corporation 
Detroit, Michigan 
Robert F. Mehl, Director 
Metals Research Laboratory 
Carnegie Institute of Technology 
P i 1 1 sb u r gh , Pe n n sy 1 va n i a 
Paul D. Merica, Vice President 

The International Nickel Co., Inc. 

New York, N. Y. 

Col. S. B. Ritchie, Chief 

Research and Development Service 
Office of the Chief of Ordnance 
^V^ar Department 
\Vashington, D. C. 

Gilbert E. Seil, Technical Consultant 
Day and Zimmerman 
Philadelphia, Pennsylvania 
Mac Short, Vice President, Engineering 
Factory “A” 

Lockheed Aircraft Corporation 
Burbank, California 
Capt. Lybrand Smith 

Office of the Chief of Research and Inventions 
Research and Development Division 
EXOS, Navy Department 
Washington, D. C. 

Col. A. E. White 

Director of Engineering Research and Professor of Metallurgy 
University of Michigan 
Ann Arbor, Michigan 
F. W, Willard, President 

Nassau Smelting 2c Refining Co, 

New York, N. Y. 

Robert S. Williams 

Head, Department of Metallurgy 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 


Col. H. H. Zornig 

Director of Laboratories 
Watertown Arsenal 
AVatertown, Massachusetts 


CONFIDENTIAL 


155 


STAFF OF WAR METALLURGY COMMITTEE 


Clyde Williams, Chairman 

Zay Jeffries, Vice Chairman 

Louis Jordan, Executive Secretary 

David C. Minton, Jr., Senior Technical Aide 

Office of the Executive Secretary 

S. L. Kruegel, Technical Aide 

L. C. Strickland, Patent Advisor 

J. E. MacQuilken, Staff Aide 

D. C. Clarke, Staff Aide 

John T. Breunich, Administrative Assistant 

J. E. Englehaupt, Administrative Assistant 

S. Pollock, Administrative Assistant 

Advisory Division 
Zay Jeffries, Chairman 

Conservation & Substitution Group, Zay Jeffries, Chairman 
Ferrous Minerals & Ferro-Alloys Group, G. E. Seil, Chairman 
Non-Metallic Minerals Group, R. P. Heuer, Chairman 
Tin Smelting & Reclamation Group, F. W. Willard, Chairman 
Alumina Group, J. D. Sullivan, Chairman 


Process Research Division 
J. D. Sullivan, Chairman 


Research Supervisors 


W. L. Badger 
H. E. Bakken 


A. J. Phillips 
C. H. Schneider 
A. E. Schuh 

G. E. Seil 

C. B. Slawson 
J. D. Sullivan 
R. K. Waring 

H. Whittaker 
A. J. Williamson 


C. H. Benedict 


W. R. Brode 
H. W. Gillett 

B, ^V. Gonser 
R. P. Heuer 
T. L. Joseph 
E. D. Martin 

C. S. Pearce 


F. \V. Willard 


156 


CONFIDENTIAL 


STAFF OF WAR METALLURGY COMMITTEE {Continued) 


Products Research Division 
H. Schnee, Chairman 


Research Supervisors 


T. X. Armstrong 

H. S. Lukens 

E. C. Bain 

C. R. Maxon 

H. C. Cross 

G. S. Mikhalapov 

H. W. Gillett 

E. E. Miller 

G. L. Craig 

D. C, ^^inton, Jr. 

Hugo Hiemke 

Albert Muller 

J. H. Humherstone 

C. S. Pearce 

A. B. Kinzel 

A. E. Schuh 

C. H. Jennings 

V. H. Schnee 

Finn Jonassen 

C. S. Smith 

P. E. Kyle 

Jerome Strauss 

L. M. Long 

A. J. Williamson 

C. H. Lorig 

L. L. Wyman 


H. J. Zoog 


Research I)i formation Division 
Richard Rimbach, Chairman 
Ralph H. Phelps, Supervisor 
H. L. Purdum, Librarian 
Katharine Forsythe, Assistant Librarian 


CONFIDENTIAL 


ARMY AND NAVY PROJECTS ASSIGNED TO DIVISION 18 
AND THE DIVISION 18 PROJECTS PERTAINING TO EACH 


The projects listed below were transmitted to the Executive Secretary, NDRC, from the War or Navy 
Department through either the War Department Liaison Officer for NDRC or the Office of Research 
and Inventions (formerly the Coordinator of Research and Development), Navy Department. 



- / 

Army or Navy 
Control Number 

Army or Navy Title and 

Dwision 18, NDRC Project Pertaining Thereto 

ACT 

Development of Beryllium Alloys Applicable to Construction of Aircraft 

NRC-7 Beryllium-Aluminum Alloys for Engine Parts 

AC-6 

Armor: Development of Nonmagnetic Armor 

B-104 &: B-208 Development of Nonmagnetic Armor Steel 

AC-75 

Development and Testing of Solid Propellants and Motors for Jet Propulsion Devices Requiring 
Large Propellant Grains 

NRC-88 Metal and Ceramic Materials for Jet Propulsion Devices 

AC-77 

Examination of Enemy Aircraft Materiel 

NRC-32 Examination of Enemy Materiel 

AC-86 

Magnesium Alloys for Oxygen Systems 

Project not undertaken 

AN-13 

Development of Noncontaminating Fifty-Five Gallon Drums for Petroleum Products 

Project not undertaken 

CE-36.01 

Investigations on Behavior of Metals Under Dynamic Conditions 

Project not undertaken (See NS-109) 

N-101 

The Corrosion-Fatigue Failure of Aircraft Control Cables 

NRC-15 Corrosion-Fatigue Failure of Aircraft Control Cables 

N-102 

Heat-Resisting Metals for Gas Turbine Parts 

SP-5 Current Data on Selected Alloys Suitable for High-Temperature Service in Gas Turbine 

and Supercharger Parts 

NRC-8 Heat-Resisting Metals for Gas Turbine Parts 

NRC-41 Heat Treatment of High-Temperature Alloys 

NRC-90 Weldability of Heat-Resisting Alloys 

N-119 

Examination of Enemy Materiel 

NRC-32 Examination of Enemy Materiel 

NA-100 

Beryllium-Aluminum Alloys for Engine Parts 

NRC-7 Beryllium-Aluminum Alloys for Engine Parts 

NA-115 

Effects of Shot Blasting on Mechanical Properties of Steel 

NRC-40 Effects of Shot Blasting on Mechanical Properties of Steel 

NRC-78 Study of Effects of Surface Prestressing on Dynamic Properties of Metals 

NA-119 

Investigation of the Effect of Impurities in Aluminum Alloys 

SP-17 Effects of Impurities in Aluminum Alloys 

NAT 26 

Forming of Aluminum Alloys 

NRC-43 Correlation of Information Available on the Fabrication of Aluminum Alloys 

SP-18 Fatigue and Impact Characteristics and Notch Effect in Tension of Artificially- Aged 

Aluminum Alloys 

NA-137 

High Temperature Properties of Light Alloys 

SP-15 High Temperature Properties of Light Alloys 

NA-Ml 

Properties and Heat Treatment of Magnesium Alloys 

NRC-21 Properties and Heat Treatment of Magnesium Alloys 

NA-145 

Fatigue Properties of Magnesium Alloys and Structures 

NRC-22 Fatigue Properties of Magnesium Alloys and Structures 

NA-146 

Formability of Magnesium Alloy Sheet 

NRC-44 Formability of Magnesium Alloy Sheet 

NA-147 

Physical and Stress-Corrosion Properties of Magnesium Alloy Sheet 

NRC-67 Physical and Stress-Corrosion Properties of Magnesium Alloy Sheet 

NA-148 

Deformation Characteristics of Magnesium Alloys 

NRC-70 Deformation Characteristics of Magnesium Alloys 

NA-149 

Plastic Flow of Aluminum Aircraft Sheets Under Combined Loads, I 

NRC-51 Plastic Flow of Aluminum Aircraft Sheets Under Combined Loads, I 

NA-150 

Plastic Flow of Aluminum Aircraft Sheets Under Combined Loads, II 

NRC-52 Plastic Flow of Aluminum Aircraft Sheets Under Combined Loads, II 

158 

CONFIDENTIAL 


Army or Navy 
Control Number 


Army or Navy Title and 
Division IS, NDRC Project Pertaining Thereto 


NCG-100 
NO-11 
NO-B-13 
NO- 159 
NS- 109 
NS-255 


NS-304 


NS-305 

NS-306 

NS-307 

NS-336 


NS-361 

OD-25 


OD-34-1 

OD-34-2 

OD-34-3 


OD-34-10 

OD-35-1 


The Influence of Peening on Weldments 
Project not undertaken 

Structural Defense Testing Facilities for Armor 

NRC-82 Behavior of Metals Under Dynamic Conditions 
Nonmagnetic Armor or Armor of Modified Magnetic Properties 
B-104 Sc B-208 Development of Nonmagnetic Armor Steel 
Bimetallic Copper Steel Rotating Bands for Projectiles 
NRC-60 Bimetallic Rotating Bands for Projectiles 

Properties of Materials at High Rates of Loading 

NRC-82 Behavior of Metals Under Dynamic Conditions 

Weldability of Steel for Hull Construction 

NRC-25 Direct Explosion Test for Welded Armor and Ship Plate 
NRC-86 Weldability of Steel for Hull Construction 

NRC-87 Investigation of Metallurgical Quality of Steels Used for Hull Construction 

Residual Stresses in Ship 4Velding 

NRC-64 Residual Stresses in Ship Welding 
NRC-89 Fatigue Tests of Ship Welds 
History of Residual Stresses on Welded Ships 

NRC-74 History of Residual Stresses in Welded Ships 
Behavior of Steel Under Multiaxial Stresses 

NRC-75 Behavior of Steel Under Conditions of Multiaxial Stresses and Effect of Welding and 
Temperature on This Behavior 

Behavior of Steel Under Conditions of Multiaxial Stress and the Effect on This Behavior of Metal- 
lographic Structure and Chemical Composition 

NRC-77 Behavior of Steel Under Conditions of Multiaxial Stress and the Effect on This Beha- 
vior of Metallographic Structure and Chemical Composition 

Investigation of Cleavage Fracture Sensitivity of Steel 

NRC-92 Cleavage Fracture of Ship Plate as Influenced by Design and Metallurgical Factors 
NRC-93 Cleavage Fracture of Ship Plate as Influenced by Size Effects 
NRC-94 Correlation of Laboratory Tests with Full Scale Ship Plate Fracture Tests 
NRC-96 Correlation of Laboratory Tests with Full Scale Ship Plate Fracture Tests 
Consulting Services to Bureau of Ships on Division 18 Projects 
Project not established, but consulting services are being rendered 
X-Ray Investigation of Residual Stresses 

B-220 Residual Stresses in Cold-Drawn Non-Ferrous Alloys 

NRC-27 Prevention of Stress-Corrosion Cracking of Cartridge Brass by Protective Coatings, or 
Surface Treatment 

Determine the Relationships between Temperature and Times of Hold at Heat for Adequate Relief 
of Stress in Welded Structures (See OD-34-2) 

Evaluate Residual Stress in Welded Structures 

B-150 Report on Research Needs in Field of Welding and Summary of Existing Knowledge 
on Welding Practice 

NRC-3 Stress Relief of Weldments for Machining Stability 
NRC-17R Stress Relief of Welded Joints 

Develop a Steel Composition That Has Maximum Strength at or Near the Solidus and That, After 
Heat Treatment, Will Have Physical Properties Suitable for Cun Manufacture 
NRC-36 Metallographic and Physical Properties of New Types of Cun Steels 
NRC-38 Improvement in Wrought Cun Tubes 
NRC-39 Improvement in Cun Steel Ingot Practice 

NRC-50 Control of Basic Open Hearth Practice for Manufacture of Wrought Cun Tubes 

NRC-80 Prevention of Cracking in Cun Tubes 

NRC-81 Development of High-Strength Cun Steels 

NRC-85 Time-Temperature-Hardness Relations in New Cun Steels 

B-90 &: B-160 Steel for Cun Tubes 

Determine the Fatigue Strength of Selected Cun Steels Under Various Combinations of Stresses 
B-189 Fatigue Strength of Selected Cun Steels 

Develop a Rapid Acceptance Test for Fire Clay Brick to be Used in Pouring Boxes for Handling 
Molten Steel Where the Brick Must Endure High Thermal Shock and Must be Strong Enough 
for Handling While Cold 

B-103 Acceptance Test for Fire Brick: Pouring Box Refractories 


CONFIDENTIAL 


159 


Army or Navy Army or Navy Title and • 

Control Number Division 18, NDRC Project Pertaining Thereto 


OD-35-2 Develop a Suitable Substitute for the Sillimanite Wet Patch for Use as Seals in Connection with the 

Pouring of Molten Steels in Special Foundry Practice 
B-95 Development of a Substitute for Sillimanite in Pouring Rings Used in Special Steel 
Foundry Practice 

OD-36-2 To Develop Precipitation Hardening Alloys That Can Be Utilized for Welding Electrodes. 

(Extended to include the development of electrodes for the repair welding of cast armor and 
for the welding of high-strength structural steels.) 

NRC-1 Weldability of Commercial Armor Plate 
NRC-2 Development of Ferritic Armor Welding Electrodes 
NRC-2R Development of Armor Welding Electrodes 
NRC-76 Development of Improved Electrode Coatings 
SP-28 Field Service in Welding of High Strength Structural Steels 
SP-29 Field Service in the Repair Welding of Cast Armor 
OD-37-1 Determine the Factual Relationship Between Structure, Allotropy, Dilation Characteristics of Steels 

Used in Ordnance 

NRC-9 Evaluation of Weldability by Direct Welding Tests 
NRC-10 Evaluation of Weldability by Direct Measurement of Cooling Rates 
NRC-1 1 Evaluation of Weldability by Correlation of Electrical and Heat Constants 
OD-38-2 Perfect a Method for the Rapid Determination of Oxygen, Hydrogen, and Nitrogen in Steel and for 

Coordinating the Effects of These Elements on the Structure and Physical Properties 
NRC-4 Effects of Hydrogen, Nitrogen, and Oxygen in Armor Plate 
OD-74 Development of a Process for Manufacturing and Welding Face-Hardened Armor 

NRC-16R Welding Face Hardened Armor 

NRC-24 The Development of a Process for Manufacturing and Welding Face-Hardened Armor 
Plate 

NRC-29 Development of Processes for the Manufacturing and Welding of Homogeneous Armor 
Plate from Nonalloy Steels 

NRC-30 Development of Processes for the Manufacturing and Welding of Case-Carburized 
Armor Plate from Nonalloy Steels 
OD-76 Direct Explosion Test for Welded Armor Plate 

NRC-25 Direct Explosion Test for Welded Armor and Ship Plate 
OD-81 Study of Properties of Malleable Iron Castings for Use in Tanks, Combat Vehicles, and Other Mili- 

tary Applications 

NRC-28 Properties of Malleable Iron Castings for Use in Tanks, Combat Vehicles, and Other 
Military Applications 

OD-82 Weldability of Commercial Armor Plate 

NRC-1 Weldability of Commercial Armor Plate 
NRC-59 Non-Metallic Welding Back-Up Strips for Armor Plate Joints 
OD-83 Correlation of Metallographic Structures and Hardness Limit in Armor Plate 

NRC-5 Correlation of Metallographic Structures and Hardness Limit in Armor Plate 
OD-84 Non-Ballistic Test for Armor Plate 

NRC-6 Non-Ballistic Test for Armor Plate 
OD-85 Spot Welding of Armor Plate and Low-Alloy Steels 

NRC-12 Spot Welding of Armor Plate and Low-Alloy Steels 
OD-86 Flash Welding of Alloy Steels for Ordnance and Non-Destructive Testing of Flash 4Velds 

NRC-1 3 Flash Welding of Alloy Steels for Ordnance 
NRC-57 Non-Destructive Testing of Flash Welds 
OD-87 Improvement of Low-Alloy Armor Steels 

NRC-14 Improvement of Low-Alloy Armor Steels 
NRC-31 Investigation of Boron in Armor Plate 
OD-88 Flame Hardening of Homogeneous Armor Plate 

NRC-23 Determination of the Effects of Flame Hardening on the Ballistic Properties of Pre- 
Heat-Treated Homogeneous Armor Plate 

OD-106 Effect of Locked-up Stresses on Ballistic Performance of Welded Armor 

NRC-53 Effect of Locked-up Stresses on Ballistic Performance of Welded Armor 
OD-107 Non-Alloy Steels for Armor-Piercing Capped Shot 

NRC-37 Investigation of the Use of Special Non-Alloy Steels for Armor-Piercing Capped Shot 
OD-108 Centrifugal Casting Methods for Production of Miscellaneous War Materiel Items 

SP-10 Mathematics underlying the Centrifugal Casting of Metals (OD-108) 

NRC-26 Improvements in and Extension of Centrifugal Casting Methods for Production of 
Miscellaneous War Materiel Items 

NRC-33 Analysis of Heat Flow in Metal Molds for Centrifugal Casting of Gun Tubes, Airplane 
Cylinders, Tank Bogey Wheels and Other War Materiel 
NRC-34N Bibliography on Centrifugal Casting 


160 


CONFIDENTIAL 


I 


Army or Navy 
Control Number 

Artiiy or Navy Title and 

Division 18, NDRC Project Pertaining Thereto 

OD-113 

Examination of Enemy Materiel 

NRC-32 Examination of Enemy Materiel 

OD-114 

Investigation of Acceptance Tests for Plain Carbon Steel Gun Forgings and Other Ordnance 

OD-115 

Forgings 

NRC-58 Acceptance Tests for Plain Carbon Steel Gun Forgings and Other Ordnance Forgings 
Heat Treatment of National Emergency Steels for Use in Tanks, Combat Cars, Gun Mounts, and 
Other Ordnance Materiel 

NRC-55 Heat Treatment of National Emergency Steels for Use in Tanks, Combat Cars, Gun 
Mounts, and Other Ordnance Materiel 

OD-117 

Study of Density and Volume Changes Associated with Phase Changes in Brass 

NRC-62 Study of Density-Volume Changes Associated with Phase Changes in Cartridge Brass 

OD-123 

Evaluation of Factors Affecting Crack Sensitivity of Welded Joints 

NRC-65 Evaluation of Factors Affecting Crack Sensitivity of Welded Joints 

OD-136 

Effect of Oxygen Cutting on Weldability of Armor Plate 

NRC-71 Effect of Oxygen Cutting on Weldability of Armor Plate 

OD-144 

Development and Extension of Precision Casting Methods for Production of Miscellaneous War 
Materiel Items 

NRC-69 Development and Extension of Precision Casting Methods for Production of Miscella- 
neous War Materiel Items 

OD-156 

Investigation of the Effect of Impurities on Ferro-Magnetism of Nonferrous Alloys 

NRC-79 Effects of Impurities on the Ferro-Magnetism of Nonferrous Alloys 

OD-177 

Manual on Effects of Shot Peening of Machine Parts and Laboratory Specimens 

QMC-18 

Project not undertaken (see NA-115) 

Development of a Suitable and Noncritical Coating for Steel in Cooking Utensils 

NRC-46 Development of a Suitable and Noncritical Fused Inorganic Coating for Cooking Uten- 
sils and Other Quartermaster’s Items 

QMC-21 

Flatware for Army Use 

NRC-48 Flatware for Army Use 

SP- 1 1 Silver Plating of Steel Flatware 

QMC-25 

Camouflage of Mess Gear 

NRC-54 Metallurgical Studies and Surveys of Army Quartermaster Corps Supplies 

QMC-39 

Corrosion-Resisting Alloy for Quartermaster Items 

NRC-91 Development and Evaluation of an Economical Corrosion-Resisting Alloy for Quarter- 
master Items 

SOS-3 

Possibilities of Interchangeable Use of the Materials and Alloys of the Platinum Group, Silver, 
Tungsten, and Others in Electrical Contacts 

SP-16 Rare Metal Contacts 


CONFIDENTIAL 


161 


CONI RACT NUMBERS, CQxNTRACTORS, AND SUBJECTS OF CONTRACTS 


Contract Number 


Contractor 


Subject 


OEMsr-307 

NDCrc-160 

NDCrc-120 

OEMsr-143 

NDCrc-181 

OEMsr-17 

OEMsr-185 

OEMsr-190 

OEMsr-68 

OEMsr-152 

OEMsr-208 

OEMsr-552 

OEMsr-535 

Correlation project 
Company financed 
OEMsr-399 

OEMsr-449 

OEMsr-448 

OEMsr-417 

Symbol No, 923 
Funds transferred 
OEMsr-478 

OEMsr-447 

OEMsr-457 

OEMsr-462 

OEMsr-459 


OEMsr-509 

OEMsr-508 

OEMsr-505 

Symbol No. 934 
Funds transferred 
OEMsr-466 

OEMsr-527 

OEMsr-445 

OEMsr-396 

OEMsr-494 

OEMsr-391 


National Academy of Sciences 
University of Michigan 
Ann Arbor, Michigan 
Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 
Ohio State University Research Foundation 
Columbus, Ohio 

Massachusetts Institute of Technology 
Cambridge, Massachusetts 
Ohio State University Research Foundation 
Columbus, Ohio 
University of Michigan 
Ann Arbor, Michigan 
Lehigh University 

Bethlehem, Pennsylvania 
Federal Shipbuilding and Dry Dock Company 
Kearny, New Jersey 
Combustion Engineering Company 
New York, New York 
Rustless Iron and Steel Corporation 
Baltimore, Maryland 
Ohio State University 
Columbus, Ohio 
Battelle Memorial Institute 
Columbus, Ohio 
Battelle Memorial Institute 
Columbus, Ohio 

Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 
National Bureau of Standards 
Washington, D. C. 

American Brake Shoe Company 
Mahwah, New Jersey 
Battelle Memorial Institute 
Columbus, Ohio 
Climax Molybdenum Company 
Detroit, Michigan 
Crane Company 
Chicago, Illinois 

Federal Shipbuilding and Dry Dock Company 
(U. S. Steel Corporation) 

Kearny, New Jersey 
Lunkenheimer Company 
Cincinnati, Ohio 

Massachusetts Institute of Technology 
Cambridge, Massachusetts 
The Midvale Company 

Philadelphia, Pennsylvania 
National Bureau of Standards 
Washington, D. C. 

University of Michigan 
Ann Arbor, Michigan 
Vanadium Corporation of America 
New York, New York 
Lehigh University 

Bethlehem, Pennsylvania 
Rensselaer Polytechnic Institute 
Troy, New York 
Columbia University 
New York, New York 
Rensselaer Polytechnic Institute 
Troy, New York * 


Metallurgical Advice to OSRD— NDRC 
Literature Survey on the Low-Temperature Proper- 
ties of Metals 
Steel for Gun Tubes 

Development of a Substitute for Sillimanite in Pour- 
ing Rings Used in Special Steel Foundry Practice 
Acceptance Test for Fire Brick: Pouring Box Refrac- 
tories 

Development of Non-Magnetic Armor Steel 

Research Needs in Field of Welding and Summary 
of Existing Knowledge on Welding Practice 
Fatigue Strength of Selected Gun Steels Under Com- 
bined Stress 

Residual Stresses in Cold-Drawn Non-Ferrous Alloys 

Weldability of Commercial Armor Plate 

Development of Ferritic Armor Welding Electrodes 

Development of Armor Welding Electrodes 

Stress Relief of Weldments for Machining Stability 

Effects of Hydrogen, Nitrogen and Oxygen in Armor 
Plate 

Correlation of Metallographic Structures and Hard- 
ness Limit in Armor Plate 
Non-Ballistic Test for Armor Plate 


Beryllium-Aluminum Alloys for Engine Parts 


Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resistins: 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals 

for 

Gas 

Turbine 

Parts 

Heat-Resisting 

Metals for 

Gas Turbine Parts 


Evaluation of Weldability by Direct Welding Tests 

Evaluation of Weldability by Direct Measurement of 
Cooling Rates 

Evaluation of Weldability by Correlation of Electri- 
cal and Heat Constants 

Spot Welding of Armor Plate and Low-Alloy Steels 


162 


CONFIDENTIAI 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECTS OE CONTRACTS (Continued) 


Contract Number 

C 071 tractor 

Subject 

OEMsr-451 

Battelle Memorial Institute 

Columbus, Ohio 

Flash Welding of Alloy Steels for Ordnance 

OEMsr-450 

Battelle Memorial Institute 

Columbus, Ohio 

Improvement of Low-Alloy Armor Steels 

OEMsr-492 

John A. Roebling’s Sons Company 

Trenton, New Jersey 

Corrosion-Fatigue Failure of Aircraft Control Cables 

Correlation project 
Rock Island financed 

Rock Island Arsenal 

Rock Island, Illinois 

Welding Face-Hardened Armor 

Correlation project 
Rock Island financed 

Rock Island Arsenal 

Rock Island, Illinois 

Stress Relief of Welded Joints 

OEMsr-647 

University of California 

Berkeley, California 

Properties and Heat Treatment of Magnesium Alloys 

OEMsr-729 

Battelle Memorial Institute 

Columbus, Ohio 

Fatigue Properties of Magnesium Alloys and Struc- 
tures 

OEMsr-547 

Massachusetts Institute of Technology 
Cambridge, Massachusetts 

Determination of the Effects of Flame Hardening on 
the Ballistic Properties of Pre Heat-Treated Homo- 
geneous Armor Plate 

OEMsr-970 

Buick Motors Division 

The Development of a Process for Manufacturing 

General Motors Corporation 

Flint, Michigan 

and Welding Face-Hardened Armor Plate 

OEMsr-712 

Trojan Powder Company 

Allentown, Pennsylvania 

Direct Explosion Test for Welded Armor and Ship 
Plate 

OEMsr-650 

U. S. Pipe and Foundry Company 

Burlington, New Jersey 

Improvements in and Extension of Centrifugal Cast- 
ing Methods for Production of Miscellaneous War 
Materiel Items 

OEMsr-645 

New Jersey Zinc Company 

Palmerton, Pennsylvania 

Prevention of Stress-Corrosion Cracking of Cartridge 
Brass by Protective Coatings or Surface Treatment 

OEMsr-730 

Battelle Memorial Institute 

Columbus, Ohio 

Properties of Malleable Iron Castings for Use in Tanks, 
Combat Vehicles and Other Military Applications 

OEMsr-975 

Buick Motor Division 

General Motors Corporation 

Flint, Michigan 

Development of Processes for the Manufacturing and 
Welding of Homogeneous Armor Plate from Non- 
Alloy Steels 

OEMsr-971 

Buick Motor Division 

General Motors Corporation 

Flint, Michigan 

Development of Processes for the Manufacturing and 
Welding of Case-Carburized Armor Plate from 
Non- Alloy Steels 

OEMsr-721 

Battelle Memorial Institute 

Columbus, Ohio 

Investigation of Boron in Armor Plate 

Symbol 1720A 

Funds transferred 

National Bureau of Standards 

Washington, D. C. 

Investigation of Boron in Armor Plate 

OEMsr-722 

Battelle Memorial Institute 

Columbus, Ohio 

Examination of Enemy Materiel 

OEMsr-731 

Battelle Memorial Institute 

Columbus, Ohio 

Analysis of Heat Flow in Metal Molds for Centrifugal 
Casting of Gun Tubes, Airplane Cylinders, Tank 
Bogey Wheels and Other War Materiel 

Correlation project 
Naval research 
Laboratory financed 

Naval Research Laboratory 

Washington, D. C. 

Bibliography on Centrifugal Casting 

Correlation project 
Company financed 

American Brake Shoe Company 

Mahwah, New Jersey 

High-Temperature Torch for Welding and Surfacing 

OEMsr-724 

University of Notre Dame Du Lac 

South Bend, Indiana 

Metallographic and Physical Properties of New Types 
of Gun Steels 

OEMsr-969 

Buick Motor Division 

General Motors Corporation 

Flint, Michigan 

Investigation of the Use of Special Non-Alloy Steels 
for Armor-Piercing Capped Shot 

OEMsr-771 

Carnegie Institute of Technology 

Pittsburgh, Pennsylvania 

Improvement in Wrought Gun Tubes 

OEMsr-755 

Carnegie Institute of Technology 

Pittsburgh, Pennsylvania 

Improvement in Gun Steel Ingot Practice 

OEMsr-1123 

Research Laboratories Division 

General Motors Corporation 

Detroit, Michigan 

Effects of Shot Blasting on Mechanical Properties of 
Steel 

OEMsr-840 

Research Laboratory 

Westinghouse Electric and Manufacturing 
Company 

East Pittsburgh, Pennsylvania 

Heat Treatment of High-Temperature Alloys 


CONFIDENTIAL 


163 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECTS OF CONTRACTS 


(Continued) 


Contract Number 


Contractor 


Subject 


OEMsr-822 

OEMsr-839 

OEMsr-819 


Case School of Applied Science 
Cleveland, Ohio 
University of California 
Berkeley, California 
Ferro Enamel Corporation 
Cleveland, Ohio 


OEMsr-902 

OEMsr-909 

OEMsr-894 

OEMsr-864 

OEMsr-877 

OEMsr-912 

OEMsr-1120 

OEMsr-973 

OEMsr-974 

OEMsr-956 

OEMsr-979 

OEMsr-1048 

Correlation project 
Company financed 
OEMsr-1084 

OEMsr-1071 

OEMsr-1030 

OEMsr-1064 

OEMsr-1033 

OEMsr-1062 

OEMsr-1103 

OEMsr-1083 

OEMsr-1187 

OEMsr-1192 

OEMsr-1217 

OEMsr-1221 

OEMsr-1270 


Reed and Barton Corporation 
Taunton, Massachusetts 
Timken Roller Bearing Company 
Canton, Ohio 

Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 
Pennsylvania State College 
State College, Pennsylvania 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 
Research Laboratory Division 
General Motors Corporation 
Detroit, Michigan 
California Institute of Technology 
Pasadena, California 
California Institute of Technology 
Pasadena, California 
Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 
Battelle Memorial Institute 
Columbus, Ohio 
General Electric Company 
Research Laboratory 
Schenectady, New York 
American Brake Shoe Company 
Mahwah, New Jersey 
University of Minnesota 
Minneapolis, Minnesota 
University of California 
Berkeley, California 
Rensselaer Polytechnic Institute 
Troy, New York 
Lehigh University 
Bethlehem, Pennsylvania 
Rensselaer Polytechnic Institute 
Troy, New York 
Rensselaer Polytechnic Institute 
Troy, New York 
General Electric Company 
Schenectady, New York 

Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 
Air Reduction Company 
New York, New York 
Massachusetts Institute of Technology 
Cambridge, Massachusetts 
University of California 
Berkeley, California 
University of California 
Berkeley, California 

Battelle Memorial Institute 
Columbus, Ohio 


Correlation of Information Available on the Fabri- 
cation of Aluminum Alloys 

Formability of Magnesium Alloy Sheet 

Development of a Suitable and Noncritical Fused 
Inorganic Coating for Cooking Utensils and Other 
Quartermaster’s Items 

Flatware for Army Use 

Control of Basic Open-Hearth Melting Practice for 
Manufacture of Wrought Gun Tubes 

Plastic Flow of Aluminum Aircraft Sheets Under 
Combined Loads, I 

Plastic Flow of Aluminum Aircraft Sheets Under 
Combined Loads, II 

Effect of Locked-Up Stresses on Ballistic Performance 
of Welded Armor 

Metallurgical Studies and Surveys of Army Quarter- 
master Corps Supplies 

Treatment of National Emergency Steels for Use in 
Tanks, Combat Cars, Gun Mounts and Other 
Ordnance Materiel 

Radiographic and Fluoroscopic Methods of Inspec- 
tion of Spot Welds in Aluminum Alloys 

Non-Destructive Testing of Flash Welds 

Acceptance Tests for Plain Carbon Steel Gun Forg- 
ings and Other Ordnance Forgings 

Non-Metallic Welding Back-Up Strips for Armor 
Plate Joints 

Bi-Metallic Rotating Bands for Projectiles 


Experimental Production of Pilot Static and Cen- 
trifugal Castings for the Armed Services 

Study of Density-Volume Changes Associated with 
Phase Changes in Cartridge Brass 

Residual Stresses in Ship Welding 

Evaluation of Factors Affecting Crack Sensitivity of 
Welded Joints 

Methods of Testing Weldability of Steel Plates and 
Shapes 

Physical and Stress-Corrosion Properties of Magne- 
sium Alloy Sheet 

Spot Welding of Magnesium Alloys 

Development and Extension of Precision Casting 
Methods for Production of Miscellaneous War Ma- 
teriel Items 

Deformation Characteristics of Magnesium Alloys 

Effect of Oxygen Cutting on Weldability of Armor 
Plate 

Investigation of Factors Reducing the Effective Duc- 
tility of Welded Steel Members 

History of Residual Stresses in Welded Ships 

Behavior of Steel Under Conditions of Multiaxial 
Stresses and Effect of Welding and Temperature on 
this Behavior 

Development of Improved Electrode Coatings 


164 


CONFIDENTIAL 


CONTRACT NUMBERS, CONTRACTORS, AND SUBJECTS OF CONTRACTS (Continued) 


Contract Number 

Contractor 

Subject 

OEMsr-1247 

Illinois Institute of Technology 

Chicago, Illinois 

Behavior of Steel Under Conditions of Multiaxial 
Stress and the Effect of Metallographic Structure 
and Chemical Composition on this Behavior 

OEMsr-1268 

General Electric Company 

Schenectady, New York 

Study of Effects of Surface Pre-Stressing on Dynamic 
Properties of Metals 

OEMsr-1249 

Lehigh University 

Bethlehem, Pennsylvania 

Effects of Impurities on the Ferromagnetism of Non- 
ferrous Alloys 

OEMsr-1265 

Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 

Prevention of Cracking in Gun Tubes 

OEMsr-1286 

Vanadium Corporation of America 

New York, New York 

Development of High-Strength Gun Steels 

OEMsr-348 

California Institute of Technology 
Pasadena, California 

Behavior of Metals Under Dynamic Conditions 

Correlation project 

American Brake Shoe Company 

Hardenability of Cast Steels for Use in Ordnance 

Company financed 

Mahwah, New Jersey 

Materiel 

Correlation project 

American Brake Shoe Company 

Heat Resistant Alloys for Ordnance Materiel and Air- 

Company financed 

Mahwah, New Jersey 

craft and Naval Engine Parts 

OEMsr-1350 

University of Pittsburgh 

Pittsburgh, Pennsylvania 

Time-Temperature-Hardness Relations in New Gun 
Steels 

OEMsr-1323 

Lehigh University 

Bethlehem, Pennsylvania 

Weldability of Steel for Hull Construction 

OEMsr-1331 

Battelle Memorial Institute 

Columbus, Ohio 

Investigation of Metallurgical Quality of Steels Used 
for Hull Construction 

OEMsr-1345 

Battelle Memorial Institute 

Columbus, Ohio 

Metal and Ceramic Materials for Jet Propulsion De- 
vices ’ - 

OEMsr-1382 

Cornell University 

Ithaca, New York 

Fatigue Tests of Ship Welds 

OEMsr-1466 

Rustless Iron and Steel Corporation 
Baltimore, Maryland 

Weldability of Heat-Resisting Alloys 

OEMsr-1400 

Battelle Memorial Institute 

Columbus, Ohio 

Development and Evaluation of an Economical Cor- 
rosion Resisting Alloy for Quartermaster Items 

OEMsr-1418 

University of California 

Berkeley, California 

Cleavage Fracture of Ship Plate as Influenced by De- 
sign and Metallurgical Factors 

OEMsr-1421 

University of Illinois 

Urbana, Illinois 

Cleavage Fracture of Ship Plate as Influenced by Size 
Effects 

OEMsr-1426 

Carnegie Institute of Technology 
Pittsburgh, Pennsylvania 

Correlation of Laboratory Tests with Full-Scale Ship 
Plate Fracture Tests 

OEMsr-1471 

Pennsylvania State College 

State College, Pennsylvania 

Correlation of Laboratory Tests with Full-Scale Ship 
Plate Fracture Tests 


CONFIDENTIAL 


165 


SURVEY PROJECTS 


Project No. 

Subject 

SP-2 

SP-5 

Industrial Applications of Chromium Plating 

Current Data on Selected Alloys Suitable for High-Temperature Service in Gas Turbine and Super- 
charger Parts (N-102) 

SP-6 

SP-8 

SP-10 

SP-11 

SP-12 

SP-14 

SP-15 

SP-16 

SP-17 

SP-18 

Abstract of Confidential Report on Nickel in Japan 

Proposed Research Project: Rivets and Rivet Steels 

Mathematics Underlying the Centrifugal Casting of Metals (OD-108) 

Silver Plating of Steel Flatware 

An Investigation of the Present Status of Magnesium Alloy Sheet in the Aircraft Industry 
Centrifugal and Precision Casting of Nonferrous Alloys: Methods of Precision Casting of Metals 
High-Temperature Properties of Light Alloys (NA-137) 

Rare Metal Electrical Contacts 

The Effect of Impurities in Aluminum Alloys (NA-119) 

Fatigue and Impact Characteristics and Notch Effect in Tension of Artificially-Aged Aluminum 
Alloys (NA-126) 

SP-19 

SP-23 

SP-24 

Review of Literature on Behavior of Metals Under Multiaxial Stresses 

Flash Welding of Aluminum 

The Test Methods of the Materials Laboratory, Engineering Division, Air Technical Service Com- 
mand, Wright Field, Dayton, Ohio 

SP-25 

SP-26 

Stress Analysis of Welded Sections 

A Survey of Research on Magnesium and Magnesium Alloys Being Conducted by Government 
Agencies, Branches of the Armed Services, and Producers and Fabricators of Magnesium 

SP-27 

SP-28 

SP-29 

SP-30 

SP-31 

SP-33 

Fatigue Properties of Aircraft Materials and Structures 

Field Service in Welding High-Strength Structural Steels (OD-36-2) 

Field Service on the Repair Welding of Cast Armor (OD-36-2) 

Suggested Research on Aluminum Alloys from Members of the Aircraft Industry 

Properties of Sheet Materials for High-Temperature Service 

Bibliography on the Damping of Metals 


166 


“L 


INDEX 


The subject indexes of all STR volumes are combined in a master index printed in a separate volume. 
For access to the index volume consult the Army or Navy Agency listed on the reverse of the half-title page. 


Aberdeen Proving Ground, armor plate 
testing, 38 

Adhesive joints for magnesium alloys, 21 
Aerojet Engineering Corporation, ce- 
ramic nozzles for rockets, 85 
Air Reduction Company, effect of oxy- 
gen cutting on weldability, 94 
Aircraft armor, 38, 49 
Aircraft control cables; see Control ca- 
bles, aircraft 
Aircraft materials, 11-33 
aluminum alloys, 11-17 
armor, 38, 49 

casting hollow round billet. 111 
control cables, 27-29 
fatigue, 32-33 

heat-resisting alloys, 81, 84 
magnesium alloys, 17-27 
molds for casting cylinders, 109 
nonmagnetic armor plate, 49 
testing methods, 32-33 
Alcuphos (special alloy steel), 119 
Allegheny Ltidlum Steel Corporation, 
heat resisting alloys, 81 
Alloys for high temperature use; see 
Heat resisting alloys 
Aluminum alloys, 11-17 
aluminum-beryllium, 16 
bulge tests, 14-15 
casting, 112 
cold rolled sheets, 1 1 
compression test, 15 
fabrication, 12-16 
fatigue, 13 
flash welding, 99 
formability limits, 13-16 
formability tests, 14 
handbook of properties, 12-13 
high-strength alloys, 12-13 
hot forming, 14 
plastic forming, 14 

radiographic and fluoroscopic inspec- 
tion of spot welds, 98 
sheet metal behavior, 14 
stress-strain relationships, 15 
tension test, 15 
test results, 15 
welding, 98-99 

Aluminum-beryllium alloys, 16 
American Brake Shoe Company; cen- 
trifugal casting, 1 1 1 
hardenability of cast steels, 45, 129 
heat resisting alloys, 84 
Ammonia corrosion test for brass car- 
tridges, 75 
Ammunition, 74-80 
armor piercing shot, 74 
cartridge brass, 74-77 
driving bands, 78-80 

Applied Mathematics Panel, centrifugal 
casting, 109 


Arc welding; heat flow during, 97 
weld metal porosity during, 90 
Armor piercing shot, 74 
Armor plate, defects; back spalling, 35, 
43 

cracking, 35 
fracture, 35 
gas impurities, 41-42 
intergranular fracture, 42 
quench-crack susceptibility, 44 
Armor plate, fabrication; heat treat- 
ment and cooling, 46-49 
flame hardening, 37 
flame softening, 37 
gas carburized, 38, 94 
melting practice, 45 
quenching, 42 

Armor plate, improvements, 36-49 
Armor plate, materials; boron alloys, 
39-46 

ferrosilicon alloys, 38-39 
high-alloy steel, 46-49 
low-alloy steel, 38-46 
nickel alloys, 46 
non-alloy steel, 38, 94 
Armor plate, testing, 34-37 
bend testing, 35 

effect of impact velocity of projectiles, 
35 

non-ballistic test, 34 
notch-bar fracture test, 35 
recommendations for further work on 
testing, 36 

testing welded armor, 36, 88 
testing with explosives, 36 
Armor plate, types; cast armor, 45 
face-hardenecl armor, 37-39 
heavy armor plate, 46-49 
nonmagnetic plate for aircraft, 49 
rolled homogeneous, 34 
Armor plate, welding, 87-99 
austenitic electrodes, 88, 92 
electrode size, 93 
ferritic electrodes, 88 
methods, 88 
oxygen cutting, 93 
recommendations for improvement, 
93 

repairing cast armor, 95 
resistance welding, 98-100 
spot welding, 98-99 
Austenitic electrodes, 88, 92 

Bainite structure of steel, 48 
Battelle Memorial Institute; boron steel 
for armor plate, 40 
case toughness on face-hardened 
armor, 38 

chromium-base alloys, 83 
examination of enemy metallurgical 
material, 114-116 


flash welding alloy steels, 90 
gases, effect on armor plate, 41-42 
heat flow in metal molds, 109 
heat resisting alloys, 84 
homogenizing heat treatment of ar- 
mor, 44 

improved electrode coatings, 90 
malleable iron in combat vehicles, 107 
metal and ceramic materials for jet 
jiropulsion, 85 

steel endurance against heat, 40 
steel for hull construction, 104-105 
welding backup strips, 93 
Beams, metal, effect of impact loading, 
123 

Bending properties of aluminum alloys, 
13-14 

Beryllium-aluminum alloys, 16 
Bore defects in gun tubes, 64-66 
Bore photography of guns, 66 
Bore quality index for guns, 66 
Boron as a substitute for molybdenum 
in steel, 40-41 

Boron treated steel; for armor piercing 
shot, 74 

in armor plate, 37, 39-41, 49 
welding, 94 

Brass cartridge cases, 74 
Brass casting, 112 

Buick Motor Division of General Mo- 
tors; case carburized armor plate 
from non-alloy steels, 38, 94 
face-hardened armor plate, mfg. and 
welding, 37, 94 

homogeneous armor jrlate, 41 
non-alloy steels for armor piercing 
shot, 74 

Bulge test, circular hydraulic, 14, 15 
Bulge tests for sheet metal, 14 
Bulge tests on aluminum alloys, 14-15 
Bureau of Standards; see National Bu- 
reau of Standards 

Cable lubricants, 28 

Cables for aircraft; see Control cables, 
aircraft 

California Institute of Technology; non- 
destructive tests of flash welding, 
99 

plastic deformation in wires and bars, 

120 

Camouflage of mess gear, 119 
Carbide nozzles for rockets, 85 
Carbon steel; army flatware, 117 
forgings, 129 
galvanized cables, 28 
hardening, 70 

Carnegie Institute of Technology; car- 
bon steel forgings, acceptance 
tests, 129 

cracking in gun tubes, 67-69 


167 


SURVEY PROJECTS 


Project No. 


Subject 


SP-2 Industrial Applications of Chromium Plating 

SP-5 Current Data on Selected Alloys Suitable for High-Temperature Service in Gas Turbine and Super- 

charger Parts (N-102) 

SP-6 Abstract of Confidential Report on Nickel in Japan 

SP-8 Proposed Research Project: Rivets and Rivet Steels 

SP-10 Mathematics Underlying the Centrifugal Casting of Metals (OD-108) 

SP-11 Silver Plating of Steel Flatware 

SP-12 An Investigation of the Present Status of Magnesium Alloy Sheet in the Aircraft Industry 

SP-I4 Centrifugal and Precision Casting of Nonferrous Alloys: Methods of Precision Casting of Metals 

SP-15 High-Temperature Properties of Light Alloys (NA-137) 

SP-16 Rare Metal Electrical Contacts 

SP-17 The Effect of Impurities in Aluminum Alloys (NA-119) 

SP-18 Fatigue and Impact Characteristics and Notch Effect in Tension of Artificially-Aged Aluminum 

Alloys (NA-126) 

SP-19 Review of Literature on Behavior of Metals Under Multiaxial Stresses 

SP-23 Flash Welding of Aluminum 

SP-24 The Test Methods of the Materials Laboratory, Engineering Division, Air Technical Service Com- 

mand, Wright Field, Dayton, Ohio 
SP-25 Stress Analysis of Welded Sections 

SP-26 A Survey of Research on Magnesium and Magnesium Alloys Being Conducted by Government 

Agencies, Branches of the Armed Services, and Producers and Fabricators of Magnesium 
SP-27 Fatigue Properties of Aircraft Materials and Structures 

SP-28 Field Service in Welding High-Strength Structural Steels (OD-36-2) 

SP-29 Field Service on the Repair Welding of Cast Armor (OD-36-2) 

SP-30 Suggested Research on Aluminum Alloys from Members of the Aircraft Industry 

SP-3I Properties of Sheet Materials for High-Temperature Service 

SP-33 Bibliography on the Damping of Metals 


166 


“L 


INDEX 


The subject indexes of all STR volumes are combined in a master index printed in a separate volume. 
For access to the index volume consult the Army or Navy Agency listed on the reverse of the half-title page. 


Aberdeen Proving Ground, armor plate 
testing, 38 

Adhesive joints for magnesium alloys, 21 
Aerojet Engineering Corporation, ce- 
ramic nozzles for rockets, 85 
Air Reduction Company, effect of oxy- 
gen cutting on weldability, 94 
Aircraft armor, 38, 49 
Aircraft control cables; see Control ca- 
bles, aircraft 
Aircraft materials, 11-33 
aluminum alloys, 11-17 
armor, 38, 49 

casting hollow round billet. 111 
control cables, 27-29 
fatigue, 32-33 

heat-resisting alloys, 81, 84 
magnesium alloys, 17-27 
molds for casting cylinders, 109 
nonmagnetic armor plate, 49 
testing methods, 32-33 
Alcuphos (special alloy steel), 119 
Allegheny Ludlum Steel Corporation, 
heat resisting alloys, 81 
Alloys for high temperature use; see 
Heat resisting alloys 
Aluminum alloys, 11-17 
aluminum-beryllium, 16 
bulge tests, 14-15 
casting, 112 
cold rolled sheets, 11 
compression test, 15 
fabrication, 12-16 
fatigue, 13 
flash welding, 99 
formability limits, 13-16 
formability tests, 14 
handbook of properties, 12-13 
high-strength alloys, 12-13 
hot forming, 14 
plastic forming, 14 

radiographic and fluoroscopic inspec- 
tion of spot welds, 98 
sheet metal behavior, 14 
stress-strain relationships, 15 
tension test, 15 
test results, 15 
welding, 98-99 

Aluminum-beryllium alloys, 16 
American Brake Shoe Company; cen- 
trifugal casting. 111 
hardenability of cast steels, 45, 129 
heat resisting alloys, 84 
Ammonia corrosion test for brass car- 
tridges, 75 
Ammunition, 74-80 
armor piercing shot, 74 
cartridge brass, 74-77 
driving bands, 78-80 

Applied Mathematics Panel, centrifugal 
casting, 109 


Arc welding; heat flow during, 97 
weld metal porosity during, 90 
Armor piercing shot, 74 
Armor plate, defects; back spalling, 35, 

43 

cracking, 35 
fracture, 35 
gas impurities, 41-42 
intergranular fracture, 42 
quench-crack susceptibility, 44 
Armor plate, fabrication; heat treat- 
ment and cooling, 46-49 
flame hardening, 37 / 

flame softening, 37 
gas carburized, 38, 94 
melting practice, 45 
quenching, 42 

Armor plate, improvements, 36-49 
Armor plate, materials; boron alloys, 
39-46 

ferrosilicon alloys, 38-39 
high-alloy steel, 46-49 
low-alloy steel, 38-46 
nickel alloys, 46 
non-alloy steel, 38, 94 
Armor plate, testing, 34-37 
bend testing, 35 

effect of impact velocity of projectiles, 
35 

non-ballistic test, 34 
notch-bar fracture test, 35 
recommendations for further work on 
testing, 36 

testing welded armor, 36, 88 
testing with explosives, 36 
Armor plate, types; cast armor, 45 
face-hardened armor, 37-39 
heavy armor plate, 46-49 
nonmagnetic plate for aircraft, 49 
rolled homogeneous, 34 
Armor plate, welding, 87-99 
austenitic electrodes, 88, 92 
electrode size, 93 
ferritic electrodes, 88 
methods, 88 
oxygen cutting, 93 
recommendations for improvement, 

93 

repairing cast armor, 95 
resistance welding, 98-100 
spot welding, 98-99 
Austenitic electrodes, 88, 92 

Bainite structure of steel, 48 
Battelle Memorial Institute; boron steel 
for armor plate, 40 
case toughness on face-hardened 
armor, 38 

chromium-base alloys, 83 
examination of enemy metallurgical 
material, 114-116 


flash welding alloy steels, 90 
gases, effect on armor plate, 41-42 
heat flow in metal molds, 109 
heat resisting alloys, 84 
homogenizing heat treatment of ar- 
mor, 44 

improved electrode coatings, 90 
malleable iron in combat vehicles, 107 
metal and ceramic materials for jet 
ptopulsion, 85 

steel endurance against heat, 40 
steel for hull construction, 104-105 
welding backup strips, 93 
Beams, metal, effect of impact loading, 
123 

Bending properties of aluminum alloys, 
13-14 

Beryllium-aluminum alloys, 16 
Bore defects in gun tubes, 64-66 
Bore photography of guns, 66 
Bore quality index for guns, 66 
Boron as a substitute for molybdenum 
in steel, 40-41 

Boron treated steel; for armor piercing 
shot, 74 

in armor plate, 37, 39-41, 49 
welding, 94 

Brass cartridge cases, 74 
Brass casting, 112 

Buick Motor Division of General Mo- 
tors; case carburized armor plate 
from non-alloy steels, 38, 94 
face-hardened armor plate, mfg. and 
welding, 37, 94 

homogeneous armor plate, 41 
non-alloy steels for armor piercing 
shot, 74 

Bulge test, circular hydraulic, 14, 15 
Bulge tests for sheet metal, 14 
Bulge tests on aluminum alloys, 14-15 
Bureau of Standards; see National Bu- 
reau of Standards 

Cable lubricants, 28 

Cables for aircraft; see Control cables, 
aircraft 

California Institute of Technology; non- 
destructive tests of flash welding, 
99 

plastic deformation in wires and bars, 

120 

Camouflage of mess gear, 119 
Carbide nozzles for rockets, 85 
Carbon steel; army flatware, 117 
forgings, 129 
galvanized cables, 28 
hardening, 70 

Carnegie Institute of Technology; car- 
bon steel forgings, acceptance 
tests, 129 

cracking in gun tubes, 67-69 


167 


168 


INDEX 


deformation characteristics of magne- 
sium alloys, 26 

improvement of gun steel ingot prac- 
tice, 64 

improvement of wrought gun tubes, 
53,56 

non-ballistic test for armor plate, 34 
plastic flow of aluminum alloy sheets, 
14 

radiographic and fluoroscopic inspec- 
tion of spot welds, 98 
ship plate fracture tests, 102 
tests of gun tube quality, 54 
Cartridge brass, 74-77 
annealing, 77 

corrosion during forming, 77 
corrosion prevention, 75-76 
electroplating, 75 
organic coatings, 76 
stress elimination, 76-77 
stress-corrosion, 75-77 
surface compression, 76 
x-ray measurements of stress, 77 
zinc coating, 75-76 
Cartridge cases; see Cartridge brass 
Cartridge coating compound, 76 
Cast armor; hardenability, 45 
repaired by welding, 95 
Cast steel; hardenability of alloy steel, 
129 

mechanical properties, 107 
temperature effects, 107 
Casting methods; centrifugal casting, 
108-111 

difficulties with aluminum-beryllium 
alloys, 16 

for aluminum alloys, 112 
for magnesium alloys, 20 
“lost wax” process, 112 
precision casting, 111-113 
Centrifugal casting, 108-111 

blanks for ball bearing races, 1 1 1 
composite grinding rolls. 111 
duplex metal casting of steel within 
copper, 1 1 1 

end connections for tank treads, 110 
heat flow in metal molds, 109 
mathematics of, 109 
methods, 110 
mortar barrels, 110 
recoil cylinders, 110 
use of monel metal, 1 10 
Ceramic nozzles for rockets, 85 
Charpy impact test for gun tubes, 54 
Chromium and chromium plated noz- 
zles for rockets, 85, 86 
Chromium plated guns, 127 
Chromium steel alloys, properties of, 83 
“Chronak” protection of zinc surfaces, 
76 

Circular hydraulic bulge test, 14-15 
Climax Molybdenum Company, new 
heat-resisting alloys, 83 
Coatings for cartridges, 76 
Coatings for cooking utensils, 117 
Cobalt-base alloys, 82 
Cold working surfaces of metals, 29-31 
Cold-rolled aluminum alloy sheets, 11 


Columbia University, mathematical 
study of heat flow during arc 
welding, 97 

Combustion Engineering Company; 

electrodes for welding heavy cast 
armor, 95 

ferritic electrodes, 89 
Compression tests for sheet metal, 15 
Control cables, aircraft, 27-29 
corrosion fatigue, 28 
fatigue failure, 28 
galvanized carbon steel cables, 28 
internal friction, 28 
lubricants, 28 
performance tests, 28 
service load tests, 28 
Cooking utensils, inorganic coatings for, 
117 

Corrosion; Alcuphos alloy, 119 
cartridge brass, 74-77 
cooking utensils, 117-119 
flatware for Army, 117-118 
magnesium alloys, 21-23 
special alloy steel, 119 
Cracking susceptibility test for gun 
tubes, 68 

Crane Company, heat resisting alloys, 81 
Crucible Steel Company, heat resisting 
alloys, 81 

Cupola malleable iron, 107, 108 
“Cycle-weld” joints in magnesium al- 
loys, 21 

Dichromate treatment of magnesium al- 
loy surfaces, 23 
Dilatometer, high speed, 45 
Dilatometric studies of armor, 45 
Dimpling magnesium alloy sheet, 19 
Division 18, NDRC; see War Metallurgy 
Division, NDRC 
Dowmetal alloys, 18 
Drawing magnesium alloy sheet, 24 
Driving bands for projectiles, 78-80 
bimetal, 78 
duplex-band, 78 
for 40 mm projectiles, 79 
for 37 mm projectiles, 79 
for 3 in. projectiles, 79 
German, 115 
sintered iron, 78 

recommendations for further research, 
80 

Ductility in gun tubes, 53 

Eddy current test for flash welding, 99 
Electrodes for welding; austenitic elec- 
trodes, 88 
coatings, 90 

composition and properties, 92 
ferritic electrodes, 88 
for heavy cast armor, 95 
for high-strength structural steels, 95 
NRC-2A electrodes, 89, 91, 95 
1/4 in. diameter electrodes, 93 
Elliptical hydraulic bulge test, 14-15 
Embrittling agents in magnesium alloys, 
26 

Enemy material, study of captured 
equipment, 114-116 


Erosion of gun steel, 52, 54 
Etching technique for magnesium alloys, 
26 

Explosives for testing armor, 36 
Explosion tests for welded armor and 
ship plate, 92, 104 

Face-hardened armor, 37-39, 98 
Fatigue of metals; aircraft structures, 
32-33 

aluminum alloys, 13 
gun steels, 72 
magnesium alloys, 20-21 
ship welds, 105 

Federal Shipbuilding and Drydock Co., 
heat resisting alloys, 81 
Ferritic electrodes, 88-91 
Ferro Enamel Corporation, fused coat- 
ings for cooking utensils, 117 
Ferromagnetic impurities in nonferrous 
alloys, 126 

Ferrosilicon, use in carburizing steel, 38 
Flame hardening of metals, 29, 37 
Flame softening of armor plate, 37 
Flash welding, 90 

Flatware for Army use, corrosion pre- 
vention, 117-118, 119 
Fluoroscopic inspection of spot welds, 98 
Forging magnesium alloys, 20 
Formability of aluminum alloys, 13-16 
Forming magnesium alloy sheet, 23-26 
40 mm Ml gun tubes; bore defects, 65 
yield strength, 65 
40 mm projectile, driving bands, 79 
Foundry materials and processes, 107-113 
centrifugal casting, 108-111 
malleable iron, 107-108 
precision casting, 111-113 
refractories, 113 

Frankford Arsenal driving band tests, 79 
Friction in aircraft control cables, 28 
Fungicide testing methods for aircraft 
materials, 32 

Gas carburizing armor, 38 
Gas turbines, heat resisting metals for, 
81,83 

Gaseous elements in armor plate, 41-42 
General Electric Company; driving 
bands for projectiles, 78 
heat resisting alloys, 81 
induction hardening, 31 
precision casting of war materials, 112 
General Motors Corporation; cooling 
rates of heavy armor plate, 47 
heat treatment of NE steels, 128 
shot blasting steel, 29-30 
German aircraft cables, 29 
German driving bands, 78 
German war products. Allied study, IM- 
HO 

Glue testing methods for aircraft mate- 
rials, 32 

Grain structure of magnesium alloys, 20 
Grainal-treated nonalloy steels, 74 
Guerin press, 24 

Gun device for embedding studs in 
metal plate, 36 


CONFIDENTIAL 


INDEX 


169 


Gun steel and guns, 51-73 
Gun steels; fatigue strength, 72 
hardenability, 69-73 
heat treatment, 69-72 
ingot practice, 64-66 
melting practices, 66-67 
new types, 72 
quality, 51-64 

recommendations for further research, 
73 

rolling and piercing practice, 66-67 
time-temperature-hardness relations, 
70 

Gun tubes; angular fracture, 64 
bore defects, 64-66 
cracking prevention, 67-69 
erosion, 52 
forgings, 57, 66 
homogenization, 64 
impact resistance, 52, 54 
maximum toughness, 52 
performance, 53 

progressive stress damage, 52, 53 
quality, 57, 66-67 
quench cracks, 68 
reasons for failure, 52-55 
seamless, 57, 64 
slack quenching, 71 
transverse impact, 60-61 
transverse reduction of area, 52, 57, 58 
upsetting, 64 
yield strength, 52, 59 
Gun tubes, specifications, 53, 55-56, 63-64 
Gun tubes, tests; cracking susceptibility, 
68 

fatigue strength, 72 
Jominy test, 70 
macroetch test, 54 
proof firing test, 54-55 
statistical analysis of results, 55, 56 
transverse Charpy impact, 54 
transverse tensile test, 54 
Guns, casting small parts, 112 

H plate testing-welding, 89 
Hadfield’s manganese steel, 49 
Hardenability of alloy steel, 129 
Hardenability of steel, 45, 47, 69-73 
Haynes Stellite Company, heat resisting 
alloys, 81 

Heat flow in metal molds, 109 
Heat resisting alloys, 81-86, 111 
centrifugal casting. 111 
chromium alloys, 83 
creep tests at different temperatures, 
82 

damping capacity, 84, 86 
for aircraft, 81, 84 

for gas turbines and turbosupercharg- 
ers, 81 

for naval engine parts, 84 
for rocket nozzles, 85 
for rockets and jet propulsion devices, 
85-86 

forged and cast alloys, 82 
laboratories engaged in work, 81 
recommendations for further research, 
83,86 


weldability, 84 

Heat treatment of magnesium alloys, 19 
Heliarc welding of magnesium alloys, 21 
Higli frecpiency surface hardening of 
metals, 29 

High temperature alloys; see Heat resist- 
ing alloys 

High-alloy homogeneous armor steel, 
46-49 

Homogenization of armor; see Low-alloy 
homogeneous armor steel 
Homogenization of gun tubes, 64 
Hot forming of aluminum alloys, 14 
Hot forming of magnesium alloys, 23-25 
HT hull steels, 104 
Hull steel weldability, 104 

Illinois Institute of Technology; ship 
steel, effect of stress, 102 
Impact resistance of gun tubes, 54 
Impact studies of metals, 120-125 
compression impact, 122 
effect of rapid loading, 125 
impact on beams, 123 
impact on plates, 123 
impact velocity, effect on tensile prop- 
erties, 121-122 

strain rates, effect on tensile proper- 
ties, 124 

Impact test for gun tubes, 54 
Induction hardening of metals, 32 
Ingot practice (steel), 64 
Intergranular fracture of steel, causes, 42 
International Harvester Company, 
NRC-2A electrode, 91 
International Nickel Company, Inc., 
heat resisting alloys, 81 
Iron, malleable; see Malleable iron 
Isothermal quenching of armor, 43 
Izod bar, 36 

- 

Japanese aircraft cables, 29 
Japanese war products, allied study of, 
114-116 

Jet propulsion devices, heat resisting 
alloys and ceramics, 85-86 
Jominy hardenability curves, 73 
Jominy hardenability test, 70, 73, 97, 
128-129 

Lead-bearing copper alloy scrap, re- 
claiming, 128 

Leather testing methods for aircraft 
materials, 32 

Lehigh University; effect of impurities 
on ferromagnetism of nonferrous 
alloys, 126 

stress elimination in nonferrous al- 
loys, 76 

weldability of hull steel, 104 
welding tests, 96, 97 
Liberty ships, study of stresses, 101 
Lithium soap lubricant for low temper- 
atures, 28 

Low temperature properties of metals, 
119 

Low-alloy homogeneous armor steel, 
39-46 


effect of boron, 39-46 
effect of gaseous elements, 41-42 
heat treating effects, 43 
homogenizing treatment, 44-46 
quench effect, 42, 43 
structure investigation, 42-43 
tempering practice, 46 
Low-alloy steels, spot welding, 98-99 
Lubricant testing methods, for aircraft 
materials, 32 

Lubricants, low temperature, 28 
Liider’s lines, 15 

Macroetch test for gun steel, 54 
Magnesium alloys, 17-27 
Magnesium alloys, fabrication; bead 
forming, 25 

deep-drawing at high temperatures, 

24 

forging, 20 
Guerin press, 24 
heat treatment, 19-20 
methods of making joints, 20 
sheet formation, 23-26 
shot peening, 30 
shrink flange formations, 24 
Magnesium alloys, properties; damping 
capacity, 19 

deformation characteristics, 26 
fatigue properties, 20-21 
formability, 23-24 
fracturing, 26 

limitations for aircraft, 21-22 
mechanical properties, 17-20 
notch efficiency and sensitivity, 17-19 
problems, 17 

stress effect of ductility, 26 
stress-corrosion, 21-23 
stress-strain, 23, 26 
stretch forming, 25 
tensile strength of sheet, 18 
Magnesium alloys, recommendations for 
further research, 26-27 
Magnesium alloys, testing; bend tests, 24 
corrosion-fatigue tests, 21 
sample size, effect on tensile proper- 
ties, 18 

Magnesium alloys, welding; heliarc- 
welding, 21 
spot welding, 98 

Magnetic materials, nonferrous alloys, 
126 

Magnetic powder test for flash welding, 
99 

Magnetic stability of aircraft armor, 49 
Malleable iron, 107-108 
comparison with cast steel, 107 
cupola malleable, 107 
effect of elevated temperatures, 107, 
108 

effect of impact, 107 
for combat vehicles, 107 
for steel substitution, 107 
mechanical properties, 107 
Manganese, Technologic Committee on, 
1 

Manganese for armor plate, 37 
Manganese steel, non-magnetic, 49 


CONFIDENTIAL 


170 


INDEX 


Martensitic structure of steel, 46, 69 
Massachusetts Institute of Technology; 
armor plate, flame hardening, 37 
heat resisting alloys, 81 
metallurgical studies of Quartermas- 
ter supplies, 1 18 
nonmagnetic armor steel, 49 
sillimanite substitute, 113 
welded armor, stresses, 89 
Melting process for steel, 45, 66 
Mess gear camouflage, 119 
Metals, behavior; compression impact, 
122 

high temperature use, 81-86 
impact loading, 120 
impact on beams, 123 
impact on plates, 123 
impact velocity, effect on tensile prop- 
erties, 121-122 

low temperature properties, 119 
multiaxial stress, 101 
rapid loading, 125 

strain rate, effect on tensile properties, 
124 

Metals for electrical contacts, rare, 127 
Microcompression test, 15 
Microstructure of steel preferred for 
shock resistance, 43 
Microtension test, 15 
Midvale Company, heat resisting alloys, 
81 

Mn-Mo welding electrode, 89 
Molds for centrifugal casting, 109 
Mortar barrels, centrifugal casting, 110 

National Bureau of Standards; boron in 
armor plate, 39 
heat resisting alloys, 81 
physical properties of steel, 40 
National emergency steels (NE steel), 
41, 128 

New Jersey Zinc Company, prevention 
of stress-corrosion of cartridge 
brass, 75 

Non-alloy steel for armor plate, 38, 94 
Nonferrous alloys; see also Heat resist- 
ing alloys 

aluminum alloys, 11-17, 112 
aluminum-beryllium, 16 

brass, 74-77, 112, 126 

bronze, 126 

chromium alloys, 83 

copper alloy scrap, lead bearing, 128 

Dowmetal, 18 

effect of impurities on ferromagnet- 
ism, 126 

magnesium alloys, 17-27 
platinum alloys, 128 
stress elimination, 76 
Nonmagnetic alloys for aircraft, 126 
Nonmagnetic armor plate for aircraft, 
49 

Nonmetallic welding backup strips, 93 
Notch efficiencies of magnesium alloys, 
18 

Notched bar impact tests for metals, 108, 

120 

Notched fatigue of aluminum alloys, 13 


NRC-2A electrode, 89, 91 

Ohio State University; pouring box re- 
fractories, 113 

research needs and current practices 
in welding, 87 

Open-hearth steel melting practice, 66 
Osmium substitutes, 127 
Oxygen cutting, effect on weldability of 
armor, 93-94 

Paint test methods for aircraft materials, 
32 

Paper testing methods for aircraft ma- 
terials, 32 

Paralketone lubricant, 28 
Pennsylvania State College; plastic flow 
of aluminum alloys, 14 
ship plate fracture tests, 102 
Photographing defects in gun bores, 66 
Plastic deformation in lead, 122 
Plastic flow of aircraft materials, 13 
Plating silver directly on steel, 118 
Platinum group alloys, 128 
Pouring box refractories for steel 
foundries, 113 
Precision casting, 111-113 
aluminum and brass, 113 
gun parts, 112, 113 
“lost wax” method, 112 
nonferrous metals, 111 
small gun parts, 112 
small turbine blades, 112 
Projectiles, 74-80 

armor piercing shot, 74 
cartridge brass, 74-77 
driving bands, 78-80 
Proof firing test for gun tubes, 55 
Punching magnesium alloy sheet, 18 
Puritan Cartridge Coating Compound, 
76 

Quartermaster’s materials, 117-119 
corrosion resistance of Alcuphos, 119 
flatware for army use, 117-118 
fused coatings for cooking utensils, 
117 

mess gear camouflage, 119 
metallurgical studies, 118 
Quench cracks in gun tubes, 68 
Quench-cracking in cast armor steel, 44 
Quenching steel, 42-43, 69 

R-301 aluminum alloys, properties, 12, 
15 

Radiographic inspection of spot welds, 
98 

Rare metal electrical contacts, 127-128 
RAT quality of gun tubes, (transverse 
area reduction), 53-64 
Recoil cylinders, centrifugal casting of, 
110 

Recommendations for further research; 
aluminum alloys, 16-17 
effects of explosive impact, 125 
electrode coatings, 91 
flash welding of aluminum alloys, 99 
gun steel, 73 


heat resisting alloys, 83, 86 
magnesium alloys, 27 
projectile driving bands, 80 
ship welding, 106 
testing armor, 36 
weld metal porosity, 90 
Reed and Barton Corporation, flatware 
for army use, 1 18 

Reed springs for “buzz bombs”, 86 
Refractories for molten metal pouring 
boxes, 113 

Rensselaer Polytechnic Institute; cool- 
ing rates of weldments, 97 
crack sensitivity of welded joints, 97 
spot welding armor plate and low al- 
loy steels, 98 

spot welding magnesium alloys, 98 
stress-corrosion of magnesium alloy 
sheet, 22 

Resistance welding of armor plate, 98- 

100 

Rivets and rivet steels, 127 
Rock Island Arsenal, welding rock hard- 
ened armor, 94 
Rocket nozzles, carbide, 85 
Rockets, heat resisting alloys for, 85-86 
Roebling’s Sons Co.; aircraft control ca- 
bles, 27 

Rolling and piercing practice in steel 
manufacturing, 66 
Rotating bands; see Driving bands 
Rubber test methods for aircraft mate- 
rials, 32 

Rupture of sheet metal, mathematical 
analysis, 16 

Rustless Iron and Steel Corporation; 
austenitic electrodes, 92 
heat resisting alloys, 84 

S curves for steel transformations, 71, 73 
Scrap reclamation, lead-bearing copper 
alloys, 128 

Seamless gun tubes; bore defects, 165- 
166 

specifications, 63 
upsetting, 64 

Selenium treatment of magnesium alloy 
surfaces, 23 

75 mm gun tubes; bore defects, 65 
steels for, 65, 72 
yield strength, 59 

75S aluminum alloy, properties, 12, 14, 15 
Sheet metal compression tests, 15 
Sheet metal tension tests, 15 
Ship steel behavior; effect of loads, 101 
effect of notches, 101 
effect of rate of strain, 103 
effect of structural discontinuities, 102 
plate fracture, 102 
Ship welding, 100-106 
fatigue of, 105 

recommendations for further research, 
106 

residual stresses, 101 
Shot peening metals, 29-31 
difficulties, 30 
magnesium alloys, 30 
process manual, 32 


CONFIDENTIAL 


INDEX 


171 


steel, 29-30 

Sillimanite substitute, 113 
Silver in electrical contacts, 128 
Silver plating directly on steel, 118 
Slack quenching, avoidance in arnior 
plate, 41 

Slack quenching gun tubes, 71 
Slag coatings for cooking utensils, 117 
Solution heat treating of magnesium 
alloys, 19 

Spalling of armor plate, 35, 43 
Specifications 57-105-1; 53 
Specifications 57-106A; 53, 56, 58, 62, 64 
Specifications for gun tubes, 53-56, 62-64 
Specifications for the NRC-2A electrode, 
91 

Specifications ^VVXS-67; 63 
Specifications WVXS-78; 58, 63 
Specifications "WVXS-SS; 58, 63 
Specifications ^V’VXS-95; 58, 62, 64 
Specifications ^VVXS-131; 62, 64 
Spot welding of armor plate, 98-99 
Stainless steel cables, 28 
Steel; carbon steel, 28, 69, 117, 129 
cast alloy steels, 129 
centrifugal casting, 108-111 
for aircraft control cables, 27-28 
for armor piercing shot, 74 
for armor plate, 37-49 
for gas turbines, 81 
for gun tubes, 51-64 
for hull construction, 104 
for projectiles, 74 
for reinforcing concrete, 125 
for rockets and jet propelled devices, 
85-86 

hardenability, 69-73 
heat resisting alloys, 81-86, 111 
heat treatment, effect on tensile im- 
pact properties, 122 
high alloy steel, 46-49 
ingot practice, 64 
low alloy steels, 39-46 
national emergency steels, 128 
non-alloy steels, 38, 94 
weldability, 96-98 

Steel alloys for high temperature use, 81- 
86 

Steel flatware, protection from rusting, 
118 

Steel ingots, solidification, 65 
Strain gauges in plugs for weld stress 
measurement, 100 
Strain propagation in metals, 120 
Strain rate tests for metals, 124 
Strain testing of ship steel, 104 
Stress in steel, effect on transformations, 
48 

Stress relief of weldments, 94 
Stress waves in metal from impacts, 35 
Stress-corrosion; cartridge brass, 74-77 
magnesium alloys, 21-23 
Stress-strain relations; aluminum alloys, 
14 

magnesium alloys, 23-24, 26 
Stresses in ship welding, 100 
Stretching properties of aluminum al- 
loys, 13-14 


Surface peening of metals, 29-32 
Surface prestressing of metals, 29-32 
shot peening, 29-31 
induction hardening, 31-32 
Surveys of available information; fatigue 
of aircraft materials, 32 
forming of aluminum alloys, 12 
heat resisting alloys, 82, 86 
magnesium alloy sheet techniques, 21- 
22 

materials testing methods, 32 
multiaxial stresses in metals, 101 

Tank treads, casting of end connections, 
110 

Tanker ship welding stresses, 101 
Tempering gun steels, 69 ^ 

Tensile impact properties of steel, 122 
Tensile loading machine, high speed, 
125 

Tensile tests for aluminum alloys, 15 
Tensile tests for gun tubes, 54 
Textile testing methods for aircraft ma- 
terials, 32 

Timken Roller Bearing Company; melt- 
ing practice for wrought gun 
tubes, 64 

open-hearth melting process for 
wrought guns, 66 

tempering temperature for gun steel, 

71 

Tin Reclamation, Advisory Committee 
on, 1 

37 mm AP projectiles, 74 
37 mm projectile driving bands, 79 
3 in. projectile driving bands, 79 
Transformation characteristics of steel, 
46-48 

Transverse Charpy impact test for 
wrought gun tubes, 54 
Transverse impact in gun tubes, 60-61 
average quality, 60 
degree of control, 61 
variation, 61 

Transverse reduction of area in gun 
tubes; degree of control, 58-59 
effect of forging reduction, 62 
effect of reheat treatment, 61-62 
effect of yield strength, 61 
statistical studies of average quality, 
57 

variation, 57-58 

Transverse tensile test for wrought gun 
tubes, 54 

Trojan Powder Company, direct explo- 
sion tests for welded armor and 
ship plate, 36, 92 
Troopship welding stresses, 101 
Tungsten in electrical contacts, 128 
Turbine blades, casting, 112 
Turbosuperchargers, heat resisting 
metals, 81, 83 

24S-0 aluminum alloy, properties, 13, 15 
24S-T8 aluminum alloy, properties, 12 
Twinning of magnesium crystals, 26 

Union Carbide and Carbon Company, 
heat resisting alloys, 81 


Universal Cyclops Steel Corporation, 
heat resisting alloys, 81 
University of California; magnesium 
alloy formability, 23-24, 25 
ship plate fracture, 102 
University of Illinois; ship plate frac- 
ture, 102 

fatigue strength of gun steel, 72 
University of Michigan; fatigue strength 
of gun steel, 72 
heat resisting alloys, 81 
low temperature properties of metals, 
119 

University of Notre Dame; properties of 
new gun steels, 70 
slack quenching gun tubes, 71 
University of Pittsburgh, time-tempera- 
ture-hardness relations in gun 
steel, 71 

U. S. Naval Engineering Experiment 
Station, heat resisting alloys, 81 
U. S. Pipe and Foundry Company; cast- 
ing bimetal tubing for driving 
bands, 79 

centrifugally cast recoil cylinders, 110 
U. S. Steel Corporation; ballistic per- 
formance of welded armor plates, 
93 

failure of welded armor joints, 91 
heat resisting alloys, 81 

V notch Charpy values, 35 
Vanadium Corp, of America; heat resist- 
ing alloys, 81 
new gun steels, 72 
Victory ship welding, stresses, 101 
Vitallium (cobalt-base alloy), high tem- 
perature creep rate, 82 
von Karman, stress due to high velocity 
impact, 35 

von Karman theory of the propagation 
of plastic deformation in solids, 
120 

War Metallurgy Division, NDRC; 
organization of, 1-3 
research projects, 3-4 
Watertown Arsenal; pouring box refrac- 
tories, 113 

progressive stress damage of guns, 52 
transverse impact resistance of guns, 
52 

transverse reduction of areas of guns, 
52 

Wax patterns for precision casting, 112 
Wedge-curl drop test, 108 
Weld metal porosity, during arc weld- 
ing, 90 

Welding, 87-106 

Welding, mathematical and electrical 
study of heat flow, 94 
Welding Advisory Committee, 1 
Welding aluminum alloys, 98, 99 
Welding armor, 87-99 
armor and alloy steel, 87 
armor plate from non-alloy steels, 94 
backup material for welded joints, 93 
ballistic performance, 91, 93 
boron treated homogeneous armor, 94 


CONFIDENTIAL 


172 


INDEX 


crack sensitivity of welded joints, 91 
face-hardened armor, 94 
improvement of shock resistance, 91 
lack of standardized procedure, 87 
repair of cast armor, 95 
stress analysis of welded armor, 89 
weld joint defects, 84 
Welding buckets on gas turbine rotors, 
84 

\Velding electrodes; austenitic elec- 
trodes, 88, 92 
ferritic electrodes, 88 
NRC-2A electrodes, 89, 91, 95 
Welding heat resisting alloys, 84 
Welding inspection, radiographic and 
fluoroscopic, 98 

Welding methods; arc welding, 94 
flash welding, 90 
resistance welding, 98-100 
spot welding, 98-99 
Welding ships, 100-106 


fatigue fractures, 100, 105 
hull steel, 104 

stresses in ship weldments, 100 
structural failures, 100 
Welding test methods; cracking tend- 
ency measurements, 97 
direct explosion tests for welded ar- 
mor and ship plate, 36, 92 
for aircraft materials, 32 
“H” plate test for welded armor plate, 
88 

hardness measurements, 96 
Jominy hardenability test, 97 
W^eldments; cooling rate, 96-97 
stress relief, 94 

Westinghouse Electric and Mfg. Com- 
pany, heat resisting alloys, 81 
W^ood testing methods for aircraft mate- 
rials, 32 

\Vrought gun tubes; basic open-hearth 
melting process, 66-67 


steel cpiality, 52 

XA75S aluminum alloy, properties, 12 

X-ray stress measurement of non-ferrous 
alloys, 76-77 

X-ray structure analysis of magnesium, 
26 

X-ray technique of inspecting weld- 
ments, 98 

Yield strength of gun steel, 54 

Yield strength of gun tubes, 52, 59-60 
degree of control, 60 
effect of tempering, 59 
quality, 59 
variation, 59-60 

Zamac II die-cast alloy, 124 

Zinc coatings for cartridge cases, 75-76 

Zinc used for soldering iron and coppei 
together, 79 

Zirconium for armor steels, 39 



COM IDL.M lAL 


*J ' ‘/i*'* ' ' V. .‘ . ‘ ' * ’ ;<• I ^-lll 

' ' flAsMS 


Kf^^v ' i i* ' * 


k. . ‘V /A Atl ‘‘j', * ' .-, -Vl 

•> ^ ;‘:;s 






. • JMPPW'r M - .‘ I > . ‘ ‘j.:; TJr-V-s! 

»HK<' ' i' ' 'fe.;:; :^: 's^m-y 











M _ 


iW- '.' , ■ . 'i A ■/ ■ i J • '_. ; J 

;..^Y ^ ■ V- , ,. •■ -. - 7 .' : 




‘ y . i7 ■ • •'« 

• ' • * ' ‘ 4 ’ 


'Why :■ 

i' t.. r* K ' * 


, M- ••:?■•- 



rf*-, .-.w 






«'. ‘ r 


'■' V-; 

i^ 77 '.{..-.-r^y'-: •■ •' 
v 






’;'»' *’>.-/, ,;.,v 


i 









i¥ 


\(f: 


' • V ^ • 

• ♦ . ' *- - _ - 
i . .“' ’• 


£r^y . 'i '. w 




^ . ■ 



. 7 


'• ■< y^‘iy. 

,.J, . '. / . «• 


. -I?:-: :,v 


-,■• '«■'., 'I't -■ . . 



S'ifOT' < ‘yMy 

ll- ■ 




B-" ■■ •s^* 


4' .• * 'lir^' '■ i? • ‘ * 

••• i v®\V--. • ' 

Ak • 


'ir;.'"- 

’iiU' 




.. . ^ tij*’ .y . .' - - .lufilwlSC - : - L 


i ^ ^'’ ‘ - * * 

,-. <-1: ’l ' -'''*-W 

:,..J 


•V , ' 




- ^MarlxV- 

• ■' ■ ''ft'-' 



i" 


' 4 W< 


1 -,4. . f -• - 

-:r t 


• ••' '% 

7 fc' ’»"• i , > 

. '^A \ 

M'- 

'J MT'l . 


‘ ‘ -w .; - 


aB?'-:'; 


. I 






.r ,> .,4 


;, . , ^r '-i ' .‘trv 

' -■ SS 


hV‘- •■ 


i'k . < 

■,i 1 » 


' V. ' 



’ *'l ' > V '■• ^ , * • '■. 1 ' • 

■■ \ ..t '1. ■ I. '* 


Vk> 



. rTqHliWIH’® « .' , 


•\ 

h ■ .'.^ I I . 
^ ^ -4 - / t 

• ^ I 


7 ' - ‘ 

» / 

4 • r! 





I I ‘ ^ I / r 


■r; 'V 
i ■ 


, .. .■■'fj ., 


■;-> O^-'.'- JHflii ■■;■' ^::'.'8ifc#<. '■ •'•'>-^ ; "<-^y?y'y :■■•'•■ h>. 

.• ■: :mH'y' - - 1 -■ ■ ' ^ 

’ •'" *■ ■■ "" '*** ■ ‘ ' ■ ■ j E *^^' •' *■ ‘ ’ ‘'I- ■- 'i- I 


’ v’ .y j!;'> 



.■’«y.-.4 w- . • . • V- . V' 




mi 


/. U/ y*A**/^*< ■ 4 






A.^rv; 


• • ' . ' ' .- f* : ■ ’ f * 4 r- . ■■ ^ • • 7- •^'- • .•■* •':. '• - t • vr V '^IJrmiiwwnrac- 

r4‘- ■■ ■ ;■:; ■ ■ ' y ^ I^ y-nyy: y' .. ::■: ' v ' 1? 


, : . ■!■. 

*" • 4 

s' - * 

ttl% • . ‘ ' ' 





<1 


r.' J- ^ 


*• ‘ V :‘V 

•vjp*' T ^ 








. I • 










«( 





^sy^TwaJI 


h-vakij^fl 





CO 

O-J 

O) 

I 

fc(jO 

cz 

o 

o 

o . 








